- Phone
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Address
Room 410, Huatuo Building, 2038 Cao'an Road, Jiading District, Shanghai
Product Categories
Shanghai Yiqiao International Trade Co., Ltd
Spare parts 1545210 ROEMHELD
NegotiableUpdate on 05/10
- Model
- Nature of the Manufacturer
- Producers
- Product Category
- Place of Origin
Overview
EGE Elektronik's main products include flow controllers, liquid level controllers, inductive proximity switches, capacitive proximity switches, photoelectric sensors, and infrared detectors. Since 1976, EGE Spezial Sensor Co., Ltd. has developed and produced sensors for special applications in various industries for automation. The manufacturer of the company. Its product portfolio includes flow controllers, infrared, photoelectric, ultrasonic sensors, capacitive proximity switches, light barriers, and more. Spare parts 1545210 ROEMHELD
Product Details
ROEMHELD1800110
ROMHELD1541105S
ROEHMHELD0353814
ROEHMHELD0353354S
ROEMHELD1942501
ROEMHELD 1942501
ROEMHELD1893N30L12DH
ROEMHELD1893N30R12DH
ROEMHELD3614396
ROEMHELD1947400
ROEMHELD3819076
ROEMHELD1896333 VMM36
Spare parts 1545210 ROEMHELD
Spare parts 1545210 ROEMHELD
ROEMHELD18951330M90
ROEMHELD1895433VDH35
ROEMHELD1895333VDH35
ROEMHELD5700-106，15M WIRE LENGTH，WITH SCREW-IN COUPLING
ROEMHELD1545516
ROEMHELD0460656
ROEMHELD0460814
ROEMHELD0460656
ROEMHELD3829234
ROEMHELD040656
ROEMHELD1804230C
ROEMHELD1942400 is valid for the entire order
ROEMHELD1825110
ROEMHELD1942010
ROEMHELD1825010
ROEMHELD1942400
ROEMHELD1825110
ROEMHELD1942010
ROEMHELD182501
ROEMHELD1825110 is valid for the entire order
ROEMHELD1942010
ROEMHELD1942-975
ROEMHELD1883-101
ROEMHELD1883-102
ROEMHELD1942-112
ROEMHELD1942-975
ROEMHELD1942-007
ROEMHELD1296-10-0300(50-300)
ROEMHELD1755023
ROEMHELD9425-102
ROEMHELD3829-234
ROEMHELD860011223328W12
ROEMHELD1895106
ROEMHELD1294-010-170
ROEMHELD1294-010-280
ROEMHELD1804230
ROEMHELD1803230
ROEMHELD1804131
ROEMHELD1895101VI
ROEMHELD1895201VI
ROEMHELDS03903-02
ROEMHELD1462868
ROEMHELD1895101VI
ROEMHELD1895201VI
ROEMHELD1893303
ROEMHELD1893403
ROEMHELD1804131
ROEMHELD0460682
ROMHELD1548195
ROEMHELD1875303
ROEMHELD1875403
ROEMHELD2361222
ROEMHELD18961250
ROEMHELD18961249
ROMHELD1297-10-0400
ROMHELD1297-10-0500
ROMHELD1297-10-0600
ROMHELD124549
ROMHELD1546
ROEMHELD1297-10-0400
ROEMHELD1297-10-0500
ROEMHELD1895639
ROEMHELD1942990
ROEMHELD1534196B is valid for the entire order. Please verify the model
ROEMHELD1534136B + 3829289
ROEMHELD1536-136B_HUB_25 SENSOR_3929-289
ROEMHELD1544195BH95
ROEMHELD471TC-12
ROEMHELD18961036P45M
ROEMHELD1541-106XM
ROEMHELD1546165
ROEMHELD1824510A
ROEMHELD15431140
ROEMHELD15431144
ROEMHELD15431144
ROEMHELD1895503
ROEMHELD1895103
ROEMHELD1895203
ROEMHELD2954429
ROEMHELD2953100
ROEMHELD9284036
ROEMHELD1942012
ROEMHELD1825500
ROEMHELD1544513
ROEMHELD1534136B
ROEMHELD1535166B
ROEMHELD1547-265
ROEMHELD1544-513
ROEMHELD1543-516
ROEMHELD1543-513
ROEMHELD1537-146B
ROEMHELD1535166B
ROEMHELD1534136B
ROEMHELD1514-115
ROEMHELD1471-001
ROEMHELD1536136B
ROEMHELD1942300
ROEMHELD18952045
ROEMHELD1313020
ROEMHELD9730500
ROEMHELD1460001
ROEMHELD3829234
ROEMHELD0460659
ROEMHELD0460776
ROEMHELD1472001
ROEMHELD1475001
ROEMHELD1516005
ROEMHELD1543556
ROEMHELD1546105
ROEMHELD1546407
ROEMHELD1891101
ROEMHELD1891201
ROEMHELD1942000
ROEMHELD1895609
ROEMHELD0460831
ROEMHELD1283005
ROEMHELD1296120250
ROEMHELD1544165+0131156
ROEMHELD1545160L
ROEMHELD1895141M
ROEMHELD1896303VDH36
ROEMHELD2951417
ROEMHELD1895509
ROEMHELD9384006
ROEMHELD811968012
ROMHELD0132703
ROEMHELD0460656
ROEMHELD04601020
ROEMHELD1829743D00
ROEMHELD1850102M
ROEMHELD1895624M
ROEMHELD1829740D00
ROEMHELD1845L090L30M
ROMHELD9281136
ROEMHELD9281136
ROMHELD811968011
ROMHELD9384755
ROEMHELD0132732
ROMHELD9281-136
ROEMHELD3412044
ROMHELD9384735
ROEMHELD1895323
ROEMHELD1895503
ROEMHELD1942925
ROEMHELD4412974
ROEMHELD1942410P
ROEMHELD1547176
ROEMHELD1547210
ROEMHELD8755020
HELDHAIN555541-01
ROEMHELD1543105S
ROEMHELD1463101
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD1891121
ROEMHELD1801200
ROEMHELD1802200
ROEMHELD1463610
ROEMHELD1895604
ROEMHELD1895504
ROEMHELD1895604
FROEMHELD1942112
ROEMHELD804474
ROEMHELD704201
ROEMHELD1942201
ROMHELD1541105S
ROMHELD1545105S
ROEMHELD1875303
ROEMHELD1875403
ROMHELD1550196
ROMHELD3614070
ROMHELD1543523
ROMHELD1738-858
ROEMHELD9284036
ROEMHELD1896303VMH36
ROEMHELD4312151
ROEMHELD3829-234
ROEMHELD1547-513 is valid for the entire order
ROEMHELD1547-516
ROEMHELD3829-234
ROEMHELD3829-099
ROEMHELD3829234
ROEMHELD1547516
ROEMHELD0132478 1844-A0XXX24(M)
ROEMHELD0132689
ROEMHELD1942002
ROEMHELD1875303
ROEMHELD1875403
ROEMHELD1545105
ROEMHELD1543407
ROEMHELDPOINTS FOR 1843847
ROEMHELD3821246
ROEMHELD1543265
ROEMHELD1804230
ROEMHELD1942007
ROEMHELD1344165
ROEMHELD4317200
ROEMHELD8459001
ROEMHELD8145160
ROEMHELD1955932
ROEMHELD1472001
ROEMHELD1543101
ROMHELD8.2135.2820
ROEMHELD1471011M
ROEMHELDAlternative: 1824828A
ROEMHELD500071-
ROEMHELD500071
ROEMHELD1893504
ROEMHELD1893604
ROEMHELD1513020
ROEMHELD1955012
ROEMHELD120034
ROEMHELD70580
ROEMHELD199948
ROEMHELD196207
ROEMHELD1846A090R36
ROEMHELD1121987-00
ROEMHELD1846A090R36
ROEMHELD1846A090L36
ROEMHELD9208181
ROEMHELDARTICLE NO. 0460682
ROEMHELDS03642
ROEMHELDS03928
ROEMHELDS04156
ROEMHELDS03643
ROEMHELD1547175
ROEMHELD1549105
ROEMHELD1546165
ROEMHELD1297-10-0500
ROEMHELD1545210
ROEMHELD1545210
ROEMHELD1545210
ROEMHELD1294100110
ROEMHELD1545210
ROEMHELD1942300
ROEMHELD1545106
ROEMHELD1897204
ROEMHELD1955932
ROEMHELD1955932
ROEMHELD1895303VDH35
ROEMHELD1911022
ROEMHELD1434001
HELDENHAINAK ERM 280 1200 03S12-03
ROEMHELD1575105
ROEMHELD3890014
ROEMHELD1296940
ROEMHELD18951330M90
ROEMHELD1895133
ROEMHELD18931466
ROEMHELD1942002
ROEMHELD1546165
ROEMHELD9284036
ROEMHELD6852-349
ROEMHELDNR.1896303VMH36，B1.880， levorotation
ROEMHELD9284036
ROEMHELD824030500
ROEMHELD1543165
ROEMHELD1543516
ROEMHELD1893N30L12DH
ROEMHELD1893N30R12DH
DYNISCO14804100 SERIAL:711448290 014，220VACpressure controller
DYNISCOART.- NR. 1480-4-1-0-0pressure controller
DYNISCOPT4624
DYNISCOPT4634-5M-12-SIL2
DYNISCOMDA422-1/2-3.5C-23/46-GC8pressure sensor
DYNISCOPT4624
DYNISCOPT4624-35MPA-6/16-SIL2pressure sensor
DYNISCOTPT4634-1/2-5M-12/18-SIL2
DYNISCO14802101 SERIAL:657282010 007，24VDCpressure controller
DYNISCOART.- NR. 1480-2-1-0-1pressure controller
DYNISCOPT4624-5M-25/18pressure sensor
DYNISCOPT4624-15M-12-SIL2
DYNISCOART.- NR. 1480-4-1-0-0
DYNISCOPT4624-35MPA-6/16-SIL2
DYNISCOPT4624-1/2-15M-12/18-SIL2
DYNISCOPT462E-5M-6/18
DYNISCOPT4626-1/2-3M-18/18sensor
DYNISCOTYP PT462E ART. -NR. : PT462E-5M-6/18
DYNISCOART.- NR. 1480-1-0-0-0
DYNISCOART.- NR. SPX 4622-N-A-05-B-21-DP-DD-A-AF-ZZ-GC9
DYNISCOTPT463F-1/2-5M-12/18-S137-SIL2pressure sensor
DYNISCOSPX2242-S-A-00-M-22-CE-FF-BCA-ZZ-B171 Check the model, which is 500BAR. After that, it says 20MPA=200BAR. What exactly do you need
DYNISCOMDT422F-1/2-1C-15/46-B171-GC0pressure sensor
DYNISCOMDT422F-1/2-3.5C-15/46-B171-GC8pressure sensor
DYNISCOART. - NR. TPT4634-1/2-50MPA-6/18-SIL2 This quantity is validsensor
DYNISCOPT462E-35MPA-6/18
DYNISCOART.- NR. SPX 4222-N-A-00-B-21-CE-DD-A-AF-ZZ-GC9
DYNISCOPT4626-1/2-5M-6/18
DYNISCOTPT4634-1/2-3M-12/18-SIL2
DYNISCO1480pressure gauge
DYNISCOPT4624-1/2-5M-6/18-SIL2pressure sensor
DYNISCOPT4626-1/2-5M-6/18
DYNISCO2242NAOOM21HTAABCAZZB628
DYNISCOPT4626-1/2-5M-12/18pressure sensor
DYNISCOReplace 1490
DYNISCOSPX 2291EA 56M 13DPDDACAZZPressure transmitter
DYNISCOMDA462-1/2-3,5C-15/46pressure sensor
DYNISCOMDT460F-M18-1M-15-SIL2Fusion pressure sensor
DYNISCO200100
DYNISCO14804100pressure gauge
DYNISCO1480-4-1-0-0pressure gauge
DYNISCO14804101display table
DYNISCOMDT422F-1/2-2C-15/46-B171-GC0pressure sensor
DYNISCOMDT460F-M18-1M-15-SIL2Fusion pressure sensor
DYNISCO200925
DYNISCO1480-4-1-0-1display table
DYNISCOMDT462L-M18-7C-15/46
DYNISCODYMT-S-1/2-J-5-10-G-2M-F13
DYNISCOECHO-MV3-MPA-R21-UNF-6PN-S06-F18-NTR
DYNISCODYMT-S-1/2-2XJ-5-10-G
DYNISCO1480-4-1-0-1 discounted price for contracts already madedisplay table
DYNISCOPT462E-1/2-5M-6/18sensor
DYNISCOMDA462-1/2-3,5C-15/46pressure sensor
DYNISCOTPT4634-35MPA-12/18-S147-SIL2sensor
DYNISCOPT462E-3.5CB-6/18-GC8
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2 replacementsensor
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTRsensor
DYNISCO1480-4-1-0-1display table
DYNISCODYMT-F-1/2-PT100/3-0-15-G-Htemperature sensor
DYNISCOPT4624-1/2-20MPA-6/18-SIL2
DYNISCOMDT422F-1/2-2C-15/46-SIL2 replacementsensor
DYNISCO1480-4-1-0-0 is valid for the entire orderpressure gauge
DYNISCOPT390-0-15M-A191
DYNISCOMDT462FH-1/2-2C-15/46-SIL2 replacementpressure sensor
DYNISCOPT4626-M18-7CB-6/18
DYNISCOECHO-MV3-BAR-R20-UNF-6PN-S06-F18-NTR 200BAR
DYNISCODYMT-S-1/2-2XJ-5-10-G-F13
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2
DYNISCOVT460-10sensor wire
DYNISCOPT4626-M18-7CB-6/18
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR 350BAR
DYNISCODYMT-S-1/2-PT100/4-15-15-G
DYNISCOMDT420F-1/2-5C-32-SIL2pressure sensor
DYNISCOECHO-VT1-BAR-R21-UNF-6PN-S06-F18-NTR 替代
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR replacement
DYNISCOSPX 2242 at 00 m 21 ceffbcazzb 106
DYNISCOTPT4636-1/2-35MPA-6/18
DYNISCOTPT4636-1/2-10M-9/18-SIL2
DYNISCOPT462E-1/2-5M-6/18
DYNISCO4012228cable
DYNISCOMDT462F-1/2-1C-15/46-SIL2
DYNISCOIDA353-5C-10V-D21
DYNISCO1480-4-1-0-0 substitution
DYNISCOM14-70MPA-6/18
DYNISCOMDT462F-1/2-3,5C-15/46-GC8pressure sensor
DYNISCO14834100
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2
DYNISCO14834100
DYNISCO14804100
DYNISCODYMT-F-1/2-PT100/3-0-15-G-H
DYNISCO14804100
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR replacementpressure sensor
DYNISCO2281-N-G-G-AC-5-P-19-A
DYNISCO4622-N-A-05-B-21-FE-DD-A-AF-ZZ-GC8
DYNISCOATC99040011
DYNISCOMDT462F-M18-7C-15/46-SIL2 replacement
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR
DYNISCO4622-N-A-05-B-21-FE-DD-A-AF-ZZ-GC8
DYNISCOMDT462F-1/2-7C-15/46
DYNISCOSPX2243-E-A-25-K-22-FE-FF-A-CA-ZZ-B171
DYNISCOMDT462L-M18-7C-15/46
DYNISCOIDA353-5C-10V-D21
DYNISCO1480-4-1-0-1
DYNISCO1480-4-1-0-0
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR
DYNISCOTPT4634-5M-15/18-SIL2
DYNISCOIDA353-7C-10V
DYNISCO14901
DYNISCO1480-4-1-0-1
DYNISCO1480-4-1-0-0pressure gauge
DYNISCO149041000
DYNISCOD7100 IDA353-3.5C
DYNISCO9966-7914
DYNISCOMDT462F-1/2-5C-23/46-B171-SIL2pressure sensor
DYNISCO1480-4-1-0-0
DYNISCODYKE-1/2-PT100/4-15-32-G-F14
DYNISCO1A422-1/2-3.5C-23/46-GC8/000ST
DYNISCOMDT462F-1/2-5C-15/46-B171-SIL2pressure sensor
ROEMHELD1891201
ROEMHELD1942000
ROEMHELD1895609
ROEMHELD0460831
ROEMHELD1283005
ROEMHELD1296120250
ROEMHELD1544165+0131156
ROEMHELD1545160L
ROEMHELD1895141M
ROEMHELD1896303VDH36
ROEMHELD2951417
ROEMHELD1895509
ROEMHELD9384006
ROEMHELD811968012
ROMHELD0132703
ROEMHELD0460656
ROEMHELD04601020
ROEMHELD1829743D00
ROEMHELD1850102M
ROEMHELD1895624M
ROEMHELD1829740D00
ROEMHELD1845L090L30M
ROMHELD9281136
ROEMHELD9281136
ROMHELD811968011
ROMHELD9384755
ROEMHELD0132732
ROMHELD9281-136
ROEMHELD3412044
ROMHELD9384735
ROEMHELD1895323
ROEMHELD1895503
ROEMHELD1942925
ROEMHELD4412974
ROEMHELD1942410P
ROEMHELD1547176
ROEMHELD1547210
ROEMHELD8755020
HELDHAIN555541-01
ROEMHELD1543105S
ROEMHELD1463101
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD1891121
ROEMHELD1801200
ROEMHELD1802200
ROEMHELD1463610
ROEMHELD1895604
ROEMHELD1895504
ROEMHELD1895604
FROEMHELD1942112
ROEMHELD804474
ROEMHELD704201
ROEMHELD1942201
ROMHELD1541105S
ROMHELD1545105S
ROEMHELD1875303
ROEMHELD1875403
ROMHELD1550196
ROMHELD3614070
ROMHELD1543523
ROMHELD1738-858
ROEMHELD9284036
ROEMHELD1896303VMH36
ROEMHELD4312151
ROEMHELD3829-234
ROEMHELD1547-513 is valid for the entire order
ROEMHELD1547-516
ROEMHELD3829-234
ROEMHELD3829-099
ROEMHELD3829234
ROEMHELD1547516
ROEMHELD0132478 1844-A0XXX24(M)
ROEMHELD0132689
ROEMHELD1942002
ROEMHELD1875303
ROEMHELD1875403
ROEMHELD1545105
ROEMHELD1543407
ROEMHELDPOINTS FOR 1843847
ROEMHELD3821246
ROEMHELD1543265
ROEMHELD1804230
ROEMHELD1942007
ROEMHELD1344165
ROEMHELD4317200
ROEMHELD8459001
ROEMHELD8145160
ROEMHELD1955932
ROEMHELD1472001
ROEMHELD1543101
ROMHELD8.2135.2820
ROEMHELD1471011M
ROEMHELDAlternative: 1824828A
ROEMHELD500071-
ROEMHELD500071
ROEMHELD1893504
ROEMHELD1893604
ROEMHELD1513020
ROEMHELD1955012
ROEMHELD120034
ROEMHELD70580
ROEMHELD199948
ROEMHELD196207
ROEMHELD1846A090R36
ROEMHELD1121987-00
ROEMHELD1846A090R36
ROEMHELD1846A090L36
ROEMHELD9208181
ROEMHELDARTICLE NO. 0460682
ROEMHELDS03642
ROEMHELDS03928
ROEMHELDS04156
ROEMHELDEEPDRDS3-05-115-5-24V
ROEMHELD1534136B
ROEMHELD3829228
ROEMHELD1533166
ROEMHELD3829228
ROEMHELD1534136B
ROEMHELD1533166
ROEMHELD1548105BH10
ROEMHELD1535196B
ROEMHELD1547106B
ROEMHELD1534166B
ROEMHELD1544165B
ROEMHELD1533166
ROEMHELD3829228 M12X1 MM
ROEMHELD1544105
ROEMHELD1544105B
ROEMHELD1533166
ROEMHELD1533166
ROEMHELD3829-228-M12
ROEMHELD3829228
ROEMHELD1533166
ROEMHELD1533166
ROEMHELD1534136B
ROEMHELD3829228
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD1534136B
ROEMHELD1533166
ROEMHELD0460836
ROEMHELD3829228
ROMHELD1897-275
ROEMHELD1533166
ROEMHELD29453
ROMHELD1464610
ROMHELD1543513
ROMHELD1544513
ROMHELD1544516
ROMHELD1895104
ROEMHELD1461110
ROEMHELD1803230
ROEMHELD1547110
ROEMHELD0460831
ROEMHELD18931191VI
ROEMHELD1895103
ROEMHELD15431144 is valid for the entire order
ROEMHELD15431140
ROEMHELD1803131B
ROEMHELD1579856
ROEMHELD804-474
ROEMHELD804 474
ROEMHELD0460730
ROEMHELD300199
ROEMHELD3001999
ROEMHELD1845N075L43M
ROEHMHELD1543265
ROEMHELD1893303
ROEMHELD1845F090L30
ROEMHELD1844F090R24
ROEMHELD1942010
ROEMHELD18911024
ROEMHELD1545210
ROEMHELD1296100450
ROEMHELD1297100500
ROEMHELD3829234
ROEMHELD3829099
ROEMHELD3829-234
ROEMHELD1546195 is valid for the entire order
ROEMHELD1547516B
ROEMHELD1824510A
ROEMHELD1461110
ROEMHELD1804230
ROEMHELD2954-429
ROEMHELD1804-121
ROEMHELD189-101M
ROEMHELD0460937
ROEMHELD2951416
ROEMHELDDiscontinued production to replace 2954620. The external dimensions are slightly smaller, but the connection dimensions are the same.
ROEMHELD102913-03
ROEMHELD146
ROEMHELD1942012
ROEMHELD1458002
ROEMHELD0132566
ROEMHELD1953858
ROEMHELD1941820
ROEMHELD1942-017
ROEMHELD1942010
ROEMHELD1942012
ROEMHELD1942017
ROEMHELD1953858
ROEMHELD1942010
ROEMHELD1458005
ROEMHELD1942017
ROEMHELD1458002
ROEMHELD1942117
ROEMHELD1942017
ROEMHELD3709012
ROEMHELD1942112
ROEMHELD1941-820
ROEMHELD1942010
ROEMHELD3707021
ROEMHELD3710081
ROEMHELD0132466 +1953858
ROEMHELD1546-210
ROEMHELD1458-002
ROEMHELD3610246
ROEMHELD9210-145
ROEMHELD1897208VMH38
ROEMHELD132125
ROEMHELD1942112
ROEMHELD5700013
ROEMHELD18951330M90
ROEMHELD1895133
ROEMHELD1824809A
ROEMHELD1546429L
ROEMHELD1551885
ROEMHELD1550939
ROEMHELD0132071 DICHTSATZ FKM FOR 1550-1X1
ROEMHELD1545105H10
ROEMHELD1471011
ROEMHELD1935802
ROEMHELD1933808
ROEMHELD1290288
ROEMHELD1290285
ROEMHELD1297130120
ROMHELD2954-429
ROMHELD1458-002
ROMHELDRPF 12-5
ROMHELD1942-000
ROEMHELD1942000
ROEMHELD1458002
ROEMHELD2954429
ROEMHELDRPF 12-5
ROEMHELD1885-104
ROEMHELD1545165
ROEMHELD1804-110
ROEMHELD1804-110
ROEMHELD1804130
ROEMHELD1534166
ROEMHELD575
ROEMHELD575
ROEMHELD4605932
ROEMHELD1953022
ROEMHELD1942925
ROEMHELD4412974
ROEMHELD1458001
ROEMHELD1942410P
ROMHELD1953022
ROMHELD1942925
ROMHELD4412974
ROMHELD0132384
ROEMHELD1854Q090R21M
ROEMHELD8804006
ROEMHELD3614075
ROEMHELDBS4253RB075N1
ROEMHELD9425-102
The cabbage fields on both sides of Lao Zhang's north and south are divided into three parts each. Lao Zhang hopes to obtain a small portion of water flow from the main waterway through a one-time waterway modification, with the water flow velocity as similar as possible to other fields, as shown in Figure 1. In this way, Lao Zhang can rest under the shade of trees for a while without making any changes to the waterway, and all the land can be watered at the same time.
A coupler is a radio frequency device that extracts a small portion of the signal from the wireless signal backbone channel, as shown in Figure 2. Like a power divider, it is a power distribution device, but the coupler is an unequal power distribution device. The combination of couplers and power dividers is mainly used to achieve a goal - to evenly distribute the transmission power of the signal source to each antenna port of the indoor distribution system, so that the transmission power of each antenna port is basically the same.
The input port power of an ideal coupler is equal to the sum of the coupling port power and the output port power, measured in watts (W)
As shown in Figure 3.
The important indicators of a coupler are coupling degree and insertion loss. The coupling degree is the ratio of the power between the coupling port and the input port, which is generally negative in dB. The larger the absolute value of the coupling degree, the less things are taken away, and the lower the loss of the natural coupler. Insertion loss is the ratio of power between the output port and the input port. The larger the absolute value of coupling degree, the smaller the absolute value of insertion loss.
If expressed in dB, there is the following relationship:
So, the relationship between the insertion loss (dB) and coupling degree (dB) of the coupler can be expressed as:
example:
A coupler with a coupling degree of -10dB has an insertion loss of -0.5dB. Taking the absolute value and considering the dielectric loss, the insertion loss is generally larger and varies from manufacturer to manufacturer. Generally, the insertion loss can be around 0.7dB.
If the input port power is 15dBm, then the power of the coupling port of this coupler is 15dBm-10dB=5dBm, and the power of the output port is 15dBm-0.7dB=14.3dBm.
Many people may ask this question: why is energy not conserved when 5dBm+14.3dmm>15dBm? The reason is simple, quantities in dBm cannot be added together.
Applying an electrical signal to the input of the optocoupler causes the light source to emit light, and the intensity of the light depends on the magnitude of the excitation current. After this light is irradiated onto the packaged photodetector, a photocurrent is generated due to the photoelectric effect, which is led out from the output of the photodetector, thus achieving the conversion of electricity to light to electricity.
1. Working Characteristics (Taking Phototransistor as an Example)
The common mode rejection ratio inside the optocoupler is very high. Because the coupling capacitance between the light-emitting tube and the receiver is very small (within 2pF), the common mode input voltage has little effect on the output current through the inter electrode coupling capacitance, resulting in a high common mode rejection ratio.
2. Output characteristics
The output characteristics of a optocoupler refer to the relationship between the bias voltage VCE applied to the photosensitive tube and the output current IC at a certain emission current IF. When IF=0, the light-emitting diode does not emit light, and the collector output current of the photosensitive transistor at this time is called dark current, which is generally very small. When IF>0, under a certain IF effect, the corresponding IC is basically independent of VCE. The variation between IC and IF is linearly related, and the output characteristics of the optocoupler measured by a semiconductor transistor characteristic diagram instrument are similar to those of a conventional transistor.
3. Optocouplers can be used as linear couplers
Provide a bias current on the light-emitting diode, and then couple the signal voltage to the light-emitting diode through a resistor. This way, the phototransistor receives a light signal that increases or decreases in the bias current, and its output current will vary linearly with the input signal voltage. Optocouplers can also operate in a switch state to transmit pulse signals. When transmitting pulse signals, there is a certain delay time between the input signal and the output signal, and the input and output delay times of optocouplers with different structures vary greatly.
Optoelectronic testing
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1. Use a multimeter to determine the quality, as shown in Figure 3. Disconnect the input power supply and measure the resistance of pins 1 and 2 using the R × 1k gear. The forward resistance should be several hundred ohms, the reverse resistance should be several tens of thousands of ohms, and the resistance between pins 3 and 4 should be infinite. 1. Any group between pin 2 and pins 3 and 4 has an infinite resistance value. After the input terminal is powered on, the resistance of pins 3 and 4 is very small. Adjusting the resistance between pins 3 and 4 of RP indicates that the device is functioning properly. Note: The R × 10k gear cannot be used, otherwise it may cause breakdown of the transmission tube.
2. Simple testing circuit: When the power is turned on, the LED does not light up. Pressing SB will make the LED light up. Adjusting the RP and LED light intensity will change, indicating that the tested optocoupler is good.
application
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1. Composition of switch circuit
When the input signal ui is at a low level, transistor V1 is in an off state, and the current of the light-emitting diode in optocoupler B1 is approximately zero. The resistance between output terminals Q11 and Q12 is very high, which is equivalent to the switch being "disconnected"; When UI is at high level, v1 conducts and the light-emitting diode in B1 emits light. The resistance between Q11 and Q12 decreases, which is equivalent to the switch being "turned on". This circuit is in a high-level conducting state because Ui is at low level and the switch is not connected. Similarly, when there is no signal (Ui is at low level), the switch conducts, so it is in a low-level conducting state
2. Composition of Logic Circuits
The circuit is an AND gate logic circuit. The logical expression is P=A.B. In the figure, two phototransistors are connected in series. Only when the input logic levels A=1 and B=1, the output P=1. Similarly, logic circuits such as "OR gate", "NAND gate", and "OR NOT gate" can also be formed
3. Form an isolated coupling circuit
The circuit is shown in Figure 4. This is a typical AC coupled amplifier circuit. By appropriately selecting the current limiting resistor Rl of the light-emitting circuit, the current transfer ratio of B4 can be kept constant to ensure the linear amplification effect of the circuit.
4. Form a high-voltage voltage regulator circuit
The driving transistor needs to use a transistor with high voltage resistance (the driving transistor in the figure is 3DG27). When the output voltage increases, the bias voltage of V55 increases, and the forward current of the light-emitting diode in B5 increases, causing the inter electrode voltage of the photosensitive tube to decrease. The bias voltage of the junction of the tube is adjusted to decrease while the internal resistance increases, resulting in a decrease in the output voltage while maintaining its stability
5. Assemble the automatic control circuit for the lobby lighting
A is four sets of analog electronic switches (S1~S4): S1, S2, S3 are connected in parallel (to increase driving power and anti-interference ability) for the delay circuit. When it is powered on, R4 and B6 drive the bidirectional thyristor VT, which directly controls the hall lighting H; S4 and external photoresistor Rl form an environmental light detection circuit. When the door is closed, the normally closed reed switch KD installed on the door frame is subjected to the action of the magnet on the door, and its contacts are disconnected, with S1, S2, and S3 in the data open state. At night, when the host returns home and opens the door, the magnet moves away from KD and the KD contact closes. At this time, the 9V power supply is rectified and charged to C1 through R1. The voltage at both ends of C1 quickly rises to 9V. The rectified voltage, through S1, S2, S3, and R4, causes the light-emitting tube in B6 to emit light, triggering the bidirectional thyristor to conduct. VT also conducts, and H lights up, achieving automatic lighting control. After the door is closed, the magnet controls KD, the contacts are disconnected, the 9V power supply stops charging C1, and the circuit enters a delay state. C1 begins to discharge R3, and after a delay, the voltage at both ends of C1 gradually drops below the turn-on voltage (1.5v) of S1, S2, and S3. S1, S2, and S3 return to the disconnected state, causing B6 to turn off, VT to turn off, and H to turn off, achieving the delayed light off function.
Distinguish types
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Directional type
A directional coupler is a four port component with directional transmission characteristics, consisting of two pairs of transmission systems connected by coupling devices. Firstly, introduce the performance indicators of directional couplers, followed by waveguide dual hole directional couplers, dual branch directional couplers, and parallel coupled microstrip directional couplers.
1) Performance indicators of directional couplers
A directional coupler is a four port network, with port "①" as the input terminal, port "②" as the direct output terminal, port "③" as the coupled output terminal, and port "④" as the isolation terminal. Its scattering matrix is set to [S]. The performance indicators of a directional coupler include coupling degree, isolation degree, orientation degree, input standing wave ratio, and operating bandwidth. Please introduce them separately below.
2) Isolation degree
The ratio of the input power P1 of input terminal "①" to the output power P4 of isolation terminal "④" is defined as the isolation degree, denoted as I.
⑶ Orientation degree
The ratio of the output power P3 of the coupling end "③" to the output power P4 of the isolation end "④" is defined as directionality, denoted as D.
⑷ Input standing wave ratio
The standing wave ratio of input port ① when ports ②, ③, and ④ are all connected to matching loads is defined as the input standing wave ratio, denoted as ρ.
⑸ Working bandwidth
The working bandwidth refers to the frequency range within which the parameters C, I, D, and ρ of the directional coupler meet the requirements.
Types of waveguides
The waveguide dual hole directional coupler is a waveguide directional coupler, in which the main and auxiliary waveguides pass through two common narrow walls
A small hole with a distance of d=(2n+1) λ g0/4 is used to achieve coupling, where λ g0 is the waveguide wavelength corresponding to the center frequency and n is a positive integer, generally taken as n=0. The coupling hole is generally circular, but can also be of other shapes. When working at the center frequency, β d=π/2, at which point D →∞; When deviating from the center frequency, sec β d has a certain value, at which point D is no longer infinite. In fact, even at the center frequency, the directionality of the dual hole coupler is not infinite, but can only be around 30dB.
In short, the waveguide dual hole directional coupler relies on the mutual interference of waves to achieve directional output of the main waveguide, with in-phase superposition at the coupling port and inverse cancellation at the isolation port. In order to increase the coupling degree of the directional coupler and broaden the operating frequency band, a porous directional coupler can be used,
Double classification types
The dual branch directional coupler consists of a main line, a secondary line, and two branch lines, where the branch line
The length and spacing are both 1/4 of the center wavelength, as shown in Figure 5-15. The characteristic impedance of the main entrance line "①" is, the characteristic impedance of the main exit line "②" is (k is the impedance transformation ratio), the characteristic impedance of the isolation end "④" of the secondary line is, the characteristic impedance of the coupling end "③" of the secondary line is, the characteristic impedance of the parallel connection line is Z0p, and the characteristic impedances of the two branch lines are and, respectively.
Parallel types
Parallel coupled microstrip directional coupler is a type of reverse directional coupler, with its coupled output end on the same side as the main input end, as shown in the figure on the right. Port in is the input port, port out is the through port, port Ocap is the coupling port, and port "④" is the isolation port.
Technical specifications for couplers (indoor distribution)
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Table 2 Technical specifications of couplers
project
specification
5dB
7dB
10dB
15dB
20dB
insertion loss
≤1.7dB
≤1.2dB
≤0.7dB
≤0.3dB
≤0.3dB
VSW standing wave ratio
≤1.4
Coupling loss
5dB
7dB
10dB
15dB
20dB
Maximum input power
15W
Type of connector (interface)
N-Female
isolator
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Isolators, also known as inverters, experience almost no attenuation when electromagnetic waves pass through them in the forward direction, but significant attenuation when they pass through them in the reverse direction. Common isolators include harmonic isolators
There are two types: vibration type and field displacement type.
Resonant isolator
Due to the anisotropy of ferrite, under a constant magnetic field Hi, the left and right circularly polarized rotating magnetic fields that form a left and right spiral relationship with the Hi direction have different permeabilities (denoted as μ - and μ+, respectively). At a certain point on a microwave transmission line containing ferrite materials, a left-handed magnetic field is transmitted along the+z direction, and a right-handed magnetic field is transmitted along the - z direction. The two transmit the same distance, but the corresponding magnetic permeability is different. Therefore, the phase velocities of the left-handed and right-handed magnetic fields are different, resulting in different phase shifts. This is the irreversibility of ferrite phase shifts. On the other hand, ferrite exhibits ferromagnetic resonance effect and resonant absorption effect of circularly polarized magnetic field.
The so-called ferromagnetic resonance effect of ferrite refers to the maximum absorption of microwave energy by ferrite when the operating frequency ω of the magnetic field is equal to the resonant angular frequency ω 0 of ferrite. For circularly polarized magnetic fields, left and right polarized magnetic fields have different magnetic permeabilities, resulting in different absorption characteristics for both.
For a right-handed polarized magnetic field with a magnetic permeability of μ+in reverse transmission, it exhibits ferromagnetic resonance effect, while for a left-handed polarized magnetic field with a magnetic permeability of μ - in forward transmission, it does not exhibit ferromagnetic resonance characteristics, which is the resonance effect of a circularly polarized magnetic field. The ferrite resonant isolator is made by utilizing this characteristic of ferrite.
Field moving isolator
Field shift isolators are made based on the different field shift effects of ferrite on the wave modes transmitted in two directions.
It adds attenuation plates on the side of the ferrite sheet, and due to the different deviations of the fields generated by the two directions of transmission, the electric field of the wave transmitted in the forward direction (- z direction) is biased towards the side without attenuation plates, while the electric field of the wave transmitted in the reverse direction (+z direction) is biased towards the side of attenuation plates, thus achieving the isolation function of small forward attenuation and large reverse attenuation, as shown in Figure 5-32.
Due to its small size, light weight, simple structure, and wide operating frequency band, field moving isolators have been widely used in low-power applications
The cabbage fields on both sides of Lao Zhang's north and south are divided into three parts each. Lao Zhang hopes to obtain a small portion of water flow from the main waterway through a one-time waterway modification, with the water flow velocity as similar as possible to other fields, as shown in Figure 1. In this way, Lao Zhang can rest under the shade of trees for a while without making any changes to the waterway, and all the land can be watered at the same time.
A coupler is a radio frequency device that extracts a small portion of the signal from the wireless signal backbone channel, as shown in Figure 2. Like a power divider, it is a power distribution device, but the coupler is an unequal power distribution device. The combination of couplers and power dividers is mainly used to achieve a goal - to evenly distribute the transmission power of the signal source to each antenna port of the indoor distribution system, so that the transmission power of each antenna port is basically the same.
The input port power of an ideal coupler is equal to the sum of the coupling port power and the output port power, measured in watts (W)
As shown in Figure 3.
The important indicators of a coupler are coupling degree and insertion loss. The coupling degree is the ratio of the power between the coupling port and the input port, which is generally negative in dB. The larger the absolute value of the coupling degree, the less things are taken away, and the lower the loss of the natural coupler. Insertion loss is the ratio of power between the output port and the input port. The larger the absolute value of coupling degree, the smaller the absolute value of insertion loss.
If expressed in dB, there is the following relationship:
So, the relationship between the insertion loss (dB) and coupling degree (dB) of the coupler can be expressed as:
example:
A coupler with a coupling degree of -10dB has an insertion loss of -0.5dB. Taking the absolute value and considering the dielectric loss, the insertion loss is generally larger and varies from manufacturer to manufacturer. Generally, the insertion loss can be around 0.7dB.
If the input port power is 15dBm, then the power of the coupling port of this coupler is 15dBm-10dB=5dBm, and the power of the output port is 15dBm-0.7dB=14.3dBm.
Many people may ask this question: why is energy not conserved when 5dBm+14.3dmm>15dBm? The reason is simple, quantities in dBm cannot be added together.
Applying an electrical signal to the input of the optocoupler causes the light source to emit light, and the intensity of the light depends on the magnitude of the excitation current. After this light is irradiated onto the packaged photodetector, a photocurrent is generated due to the photoelectric effect, which is led out from the output of the photodetector, thus achieving the conversion of electricity to light to electricity.
1. Working Characteristics (Taking Phototransistor as an Example)
The common mode rejection ratio inside the optocoupler is very high. Because the coupling capacitance between the light-emitting tube and the receiver is very small (within 2pF), the common mode input voltage has little effect on the output current through the inter electrode coupling capacitance, resulting in a high common mode rejection ratio.
2. Output characteristics
The output characteristics of a optocoupler refer to the relationship between the bias voltage VCE applied to the photosensitive tube and the output current IC at a certain emission current IF. When IF=0, the light-emitting diode does not emit light, and the collector output current of the photosensitive transistor at this time is called dark current, which is generally very small. When IF>0, under a certain IF effect, the corresponding IC is basically independent of VCE. The variation between IC and IF is linearly related, and the output characteristics of the optocoupler measured by a semiconductor transistor characteristic diagram instrument are similar to those of a conventional transistor.
3. Optocouplers can be used as linear couplers
Provide a bias current on the light-emitting diode, and then couple the signal voltage to the light-emitting diode through a resistor. This way, the phototransistor receives a light signal that increases or decreases in the bias current, and its output current will vary linearly with the input signal voltage. Optocouplers can also operate in a switch state to transmit pulse signals. When transmitting pulse signals, there is a certain delay time between the input signal and the output signal, and the input and output delay times of optocouplers with different structures vary greatly.
Optoelectronic testing
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1. Use a multimeter to determine the quality, as shown in Figure 3. Disconnect the input power supply and measure the resistance of pins 1 and 2 using the R × 1k gear. The forward resistance should be several hundred ohms, the reverse resistance should be several tens of thousands of ohms, and the resistance between pins 3 and 4 should be infinite. 1. Any group between pin 2 and pins 3 and 4 has an infinite resistance value. After the input terminal is powered on, the resistance of pins 3 and 4 is very small. Adjusting the resistance between pins 3 and 4 of RP indicates that the device is functioning properly. Note: The R × 10k gear cannot be used, otherwise it may cause breakdown of the transmission tube.
2. Simple testing circuit: When the power is turned on, the LED does not light up. Pressing SB will make the LED light up. Adjusting the RP and LED light intensity will change, indicating that the tested optocoupler is good.
application
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edit
1. Composition of switch circuit
When the input signal ui is at a low level, transistor V1 is in an off state, and the current of the light-emitting diode in optocoupler B1 is approximately zero. The resistance between output terminals Q11 and Q12 is very high, which is equivalent to the switch being "disconnected"; When UI is at high level, v1 conducts and the light-emitting diode in B1 emits light. The resistance between Q11 and Q12 decreases, which is equivalent to the switch being "turned on". This circuit is in a high-level conducting state because Ui is at low level and the switch is not connected. Similarly, when there is no signal (Ui is at low level), the switch conducts, so it is in a low-level conducting state
2. Composition of Logic Circuits
The circuit is an AND gate logic circuit. The logical expression is P=A.B. In the figure, two phototransistors are connected in series. Only when the input logic levels A=1 and B=1, the output P=1. Similarly, logic circuits such as "OR gate", "NAND gate", and "OR NOT gate" can also be formed
3. Form an isolated coupling circuit
The circuit is shown in Figure 4. This is a typical AC coupled amplifier circuit. By appropriately selecting the current limiting resistor Rl of the light-emitting circuit, the current transfer ratio of B4 can be kept constant to ensure the linear amplification effect of the circuit.
4. Form a high-voltage voltage regulator circuit
The driving transistor needs to use a transistor with high voltage resistance (the driving transistor in the figure is 3DG27). When the output voltage increases, the bias voltage of V55 increases, and the forward current of the light-emitting diode in B5 increases, causing the inter electrode voltage of the photosensitive tube to decrease. The bias voltage of the junction of the tube is adjusted to decrease while the internal resistance increases, resulting in a decrease in the output voltage while maintaining its stability
5. Assemble the automatic control circuit for the lobby lighting
A is four sets of analog electronic switches (S1~S4): S1, S2, S3 are connected in parallel (to increase driving power and anti-interference ability) for the delay circuit. When it is powered on, R4 and B6 drive the bidirectional thyristor VT, which directly controls the hall lighting H; S4 and external photoresistor Rl form an environmental light detection circuit. When the door is closed, the normally closed reed switch KD installed on the door frame is subjected to the action of the magnet on the door, and its contacts are disconnected, with S1, S2, and S3 in the data open state. At night, when the host returns home and opens the door, the magnet moves away from KD and the KD contact closes. At this time, the 9V power supply is rectified and charged to C1 through R1. The voltage at both ends of C1 quickly rises to 9V. The rectified voltage, through S1, S2, S3, and R4, causes the light-emitting tube in B6 to emit light, triggering the bidirectional thyristor to conduct. VT also conducts, and H lights up, achieving automatic lighting control. After the door is closed, the magnet controls KD, the contacts are disconnected, the 9V power supply stops charging C1, and the circuit enters a delay state. C1 begins to discharge R3, and after a delay, the voltage at both ends of C1 gradually drops below the turn-on voltage (1.5v) of S1, S2, and S3. S1, S2, and S3 return to the disconnected state, causing B6 to turn off, VT to turn off, and H to turn off, achieving the delayed light off function.
Distinguish types
broadcast
edit
Directional type
A directional coupler is a four port component with directional transmission characteristics, consisting of two pairs of transmission systems connected by coupling devices. Firstly, introduce the performance indicators of directional couplers, followed by waveguide dual hole directional couplers, dual branch directional couplers, and parallel coupled microstrip directional couplers.
1) Performance indicators of directional couplers
A directional coupler is a four port network, with port "①" as the input terminal, port "②" as the direct output terminal, port "③" as the coupled output terminal, and port "④" as the isolation terminal. Its scattering matrix is set to [S]. The performance indicators of a directional coupler include coupling degree, isolation degree, orientation degree, input standing wave ratio, and operating bandwidth. Please introduce them separately below.
2) Isolation degree
The ratio of the input power P1 of input terminal "①" to the output power P4 of isolation terminal "④" is defined as the isolation degree, denoted as I.
⑶ Orientation degree
The ratio of the output power P3 of the coupling end "③" to the output power P4 of the isolation end "④" is defined as directionality, denoted as D.
⑷ Input standing wave ratio
The standing wave ratio of input port ① when ports ②, ③, and ④ are all connected to matching loads is defined as the input standing wave ratio, denoted as ρ.
⑸ Working bandwidth
The working bandwidth refers to the frequency range within which the parameters C, I, D, and ρ of the directional coupler meet the requirements.
Types of waveguides
The waveguide dual hole directional coupler is a waveguide directional coupler, in which the main and auxiliary waveguides pass through two common narrow walls
A small hole with a distance of d=(2n+1) λ g0/4 is used to achieve coupling, where λ g0 is the waveguide wavelength corresponding to the center frequency and n is a positive integer, generally taken as n=0. The coupling hole is generally circular, but can also be of other shapes. When working at the center frequency, β d=π/2, at which point D →∞; When deviating from the center frequency, sec β d has a certain value, at which point D is no longer infinite. In fact, even at the center frequency, the directionality of the dual hole coupler is not infinite, but can only be around 30dB.
In short, the waveguide dual hole directional coupler relies on the mutual interference of waves to achieve directional output of the main waveguide, with in-phase superposition at the coupling port and inverse cancellation at the isolation port. In order to increase the coupling degree of the directional coupler and broaden the operating frequency band, a porous directional coupler can be used,
Double classification types
The dual branch directional coupler consists of a main line, a secondary line, and two branch lines, where the branch line
The length and spacing are both 1/4 of the center wavelength, as shown in Figure 5-15. The characteristic impedance of the main entrance line "①" is, the characteristic impedance of the main exit line "②" is (k is the impedance transformation ratio), the characteristic impedance of the isolation end "④" of the secondary line is, the characteristic impedance of the coupling end "③" of the secondary line is, the characteristic impedance of the parallel connection line is Z0p, and the characteristic impedances of the two branch lines are and, respectively.
Parallel types
Parallel coupled microstrip directional coupler is a type of reverse directional coupler, with its coupled output end on the same side as the main input end, as shown in the figure on the right. Port in is the input port, port out is the through port, port Ocap is the coupling port, and port "④" is the isolation port.
Technical specifications for couplers (indoor distribution)
broadcast
edit
Table 2 Technical specifications of couplers
project
specification
5dB
7dB
10dB
15dB
20dB
insertion loss
≤1.7dB
≤1.2dB
≤0.7dB
≤0.3dB
≤0.3dB
VSW standing wave ratio
≤1.4
Coupling loss
5dB
7dB
10dB
15dB
20dB
Maximum input power
15W
Type of connector (interface)
N-Female
isolator
broadcast
edit
Isolators, also known as inverters, experience almost no attenuation when electromagnetic waves pass through them in the forward direction, but significant attenuation when they pass through them in the reverse direction. Common isolators include harmonic isolators
There are two types: vibration type and field displacement type.
Resonant isolator
Due to the anisotropy of ferrite, under a constant magnetic field Hi, the left and right circularly polarized rotating magnetic fields that form a left and right spiral relationship with the Hi direction have different permeabilities (denoted as μ - and μ+, respectively). At a certain point on a microwave transmission line containing ferrite materials, a left-handed magnetic field is transmitted along the+z direction, and a right-handed magnetic field is transmitted along the - z direction. The two transmit the same distance, but the corresponding magnetic permeability is different. Therefore, the phase velocities of the left-handed and right-handed magnetic fields are different, resulting in different phase shifts. This is the irreversibility of ferrite phase shifts. On the other hand, ferrite exhibits ferromagnetic resonance effect and resonant absorption effect of circularly polarized magnetic field.
The so-called ferromagnetic resonance effect of ferrite refers to the maximum absorption of microwave energy by ferrite when the operating frequency ω of the magnetic field is equal to the resonant angular frequency ω 0 of ferrite. For circularly polarized magnetic fields, left and right polarized magnetic fields have different magnetic permeabilities, resulting in different absorption characteristics for both.
For a right-handed polarized magnetic field with a magnetic permeability of μ+in reverse transmission, it exhibits ferromagnetic resonance effect, while for a left-handed polarized magnetic field with a magnetic permeability of μ - in forward transmission, it does not exhibit ferromagnetic resonance characteristics, which is the resonance effect of a circularly polarized magnetic field. The ferrite resonant isolator is made by utilizing this characteristic of ferrite.
Field moving isolator
Field shift isolators are made based on the different field shift effects of ferrite on the wave modes transmitted in two directions.
It adds attenuation plates on the side of the ferrite sheet, and due to the different deviations of the fields generated by the two directions of transmission, the electric field of the wave transmitted in the forward direction (- z direction) is biased towards the side without attenuation plates, while the electric field of the wave transmitted in the reverse direction (+z direction) is biased towards the side of attenuation plates, thus achieving the isolation function of small forward attenuation and large reverse attenuation, as shown in Figure 5-32.
Due to its small size, light weight, simple structure, and wide operating frequency band, field moving isolators have been widely used in low-power applications
ROEMHELD1800110
ROMHELD1541105S
ROEHMHELD0353814
ROEHMHELD0353354S
ROEMHELD1942501
ROEMHELD 1942501
ROEMHELD1893N30L12DH
ROEMHELD1893N30R12DH
ROEMHELD3614396
ROEMHELD1947400
ROEMHELD3819076
ROEMHELD1896333 VMM36
ROEMHELD18951330M90
ROEMHELD1895433VDH35
ROEMHELD1895333VDH35
ROEMHELD5700-106，15M WIRE LENGTH，WITH SCREW-IN COUPLING
ROEMHELD1545516
ROEMHELD0460656
ROEMHELD0460814
ROEMHELD0460656
ROEMHELD3829234
ROEMHELD040656
ROEMHELD1804230C
ROEMHELD1942400 is valid for the entire order
ROEMHELD1825110
ROEMHELD1942010
ROEMHELD1825010
ROEMHELD1942400
ROEMHELD1825110
ROEMHELD1942010
ROEMHELD182501
ROEMHELD1825110 is valid for the entire order
ROEMHELD1942010
ROEMHELD1942-975
ROEMHELD1883-101
ROEMHELD1883-102
ROEMHELD1942-112
ROEMHELD1942-975
ROEMHELD1942-007
ROEMHELD1296-10-0300(50-300)
ROEMHELD1755023
ROEMHELD9425-102
ROEMHELD3829-234
ROEMHELD860011223328W12
ROEMHELD1895106
ROEMHELD1294-010-170
ROEMHELD1294-010-280
ROEMHELD1804230
ROEMHELD1803230
ROEMHELD1804131
ROEMHELD1895101VI
ROEMHELD1895201VI
ROEMHELDS03903-02
ROEMHELD1462868
ROEMHELD1895101VI
ROEMHELD1895201VI
ROEMHELD1893303
ROEMHELD1893403
ROEMHELD1804131
ROEMHELD0460682
ROMHELD1548195
ROEMHELD1875303
ROEMHELD1875403
ROEMHELD2361222
ROEMHELD18961250
ROEMHELD18961249
ROMHELD1297-10-0400
ROMHELD1297-10-0500
ROMHELD1297-10-0600
ROMHELD124549
ROMHELD1546
ROEMHELD1297-10-0400
ROEMHELD1297-10-0500
ROEMHELD1895639
ROEMHELD1942990
ROEMHELD1534196B is valid for the entire order. Please verify the model
ROEMHELD1534136B + 3829289
ROEMHELD1536-136B_HUB_25 SENSOR_3929-289
ROEMHELD1544195BH95
ROEMHELD471TC-12
ROEMHELD18961036P45M
ROEMHELD1541-106XM
ROEMHELD1546165
ROEMHELD1824510A
ROEMHELD15431140
ROEMHELD15431144
ROEMHELD15431144
ROEMHELD1895503
ROEMHELD1895103
ROEMHELD1895203
ROEMHELD2954429
ROEMHELD2953100
ROEMHELD9284036
ROEMHELD1942012
ROEMHELD1825500
ROEMHELD1544513
ROEMHELD1534136B
ROEMHELD1535166B
ROEMHELD1547-265
ROEMHELD1544-513
ROEMHELD1543-516
ROEMHELD1543-513
ROEMHELD1537-146B
ROEMHELD1535166B
ROEMHELD1534136B
ROEMHELD1514-115
ROEMHELD1471-001
ROEMHELD1536136B
ROEMHELD1942300
ROEMHELD18952045
ROEMHELD1313020
ROEMHELD9730500
ROEMHELD1460001
ROEMHELD3829234
ROEMHELD0460659
ROEMHELD0460776
ROEMHELD1472001
ROEMHELD1475001
ROEMHELD1516005
ROEMHELD1543556
ROEMHELD1546105
ROEMHELD1546407
ROEMHELD1891101
ROEMHELD1891201
ROEMHELD1942000
ROEMHELD1895609
ROEMHELD0460831
ROEMHELD1283005
ROEMHELD1296120250
ROEMHELD1544165+0131156
ROEMHELD1545160L
ROEMHELD1895141M
ROEMHELD1896303VDH36
ROEMHELD2951417
ROEMHELD1895509
ROEMHELD9384006
ROEMHELD811968012
ROMHELD0132703
ROEMHELD0460656
ROEMHELD04601020
ROEMHELD1829743D00
ROEMHELD1850102M
ROEMHELD1895624M
ROEMHELD1829740D00
ROEMHELD1845L090L30M
ROMHELD9281136
ROEMHELD9281136
ROMHELD811968011
ROMHELD9384755
ROEMHELD0132732
ROMHELD9281-136
ROEMHELD3412044
ROMHELD9384735
ROEMHELD1895323
ROEMHELD1895503
ROEMHELD1942925
ROEMHELD4412974
ROEMHELD1942410P
ROEMHELD1547176
ROEMHELD1547210
ROEMHELD8755020
HELDHAIN555541-01
ROEMHELD1543105S
ROEMHELD1463101
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD1891121
ROEMHELD1801200
ROEMHELD1802200
ROEMHELD1463610
ROEMHELD1895604
ROEMHELD1895504
ROEMHELD1895604
FROEMHELD1942112
ROEMHELD804474
ROEMHELD704201
ROEMHELD1942201
ROMHELD1541105S
ROMHELD1545105S
ROEMHELD1875303
ROEMHELD1875403
ROMHELD1550196
ROMHELD3614070
ROMHELD1543523
ROMHELD1738-858
ROEMHELD9284036
ROEMHELD1896303VMH36
ROEMHELD4312151
ROEMHELD3829-234
ROEMHELD1547-513 is valid for the entire order
ROEMHELD1547-516
ROEMHELD3829-234
ROEMHELD3829-099
ROEMHELD3829234
ROEMHELD1547516
ROEMHELD0132478 1844-A0XXX24(M)
ROEMHELD0132689
ROEMHELD1942002
ROEMHELD1875303
ROEMHELD1875403
ROEMHELD1545105
ROEMHELD1543407
ROEMHELDPOINTS FOR 1843847
ROEMHELD3821246
ROEMHELD1543265
ROEMHELD1804230
ROEMHELD1942007
ROEMHELD1344165
ROEMHELD4317200
ROEMHELD8459001
ROEMHELD8145160
ROEMHELD1955932
ROEMHELD1472001
ROEMHELD1543101
ROMHELD8.2135.2820
ROEMHELD1471011M
ROEMHELDAlternative: 1824828A
ROEMHELD500071-
ROEMHELD500071
ROEMHELD1893504
ROEMHELD1893604
ROEMHELD1513020
ROEMHELD1955012
ROEMHELD120034
ROEMHELD70580
ROEMHELD199948
ROEMHELD196207
ROEMHELD1846A090R36
ROEMHELD1121987-00
ROEMHELD1846A090R36
ROEMHELD1846A090L36
ROEMHELD9208181
ROEMHELDARTICLE NO. 0460682
ROEMHELDS03642
ROEMHELDS03928
ROEMHELDS04156
ROEMHELDS03643
ROEMHELD1547175
ROEMHELD1549105
ROEMHELD1546165
ROEMHELD1297-10-0500
ROEMHELD1545210
ROEMHELD1545210
ROEMHELD1545210
ROEMHELD1294100110
ROEMHELD1545210
ROEMHELD1942300
ROEMHELD1545106
ROEMHELD1897204
ROEMHELD1955932
ROEMHELD1955932
ROEMHELD1895303VDH35
ROEMHELD1911022
ROEMHELD1434001
HELDENHAINAK ERM 280 1200 03S12-03
ROEMHELD1575105
ROEMHELD3890014
ROEMHELD1296940
ROEMHELD18951330M90
ROEMHELD1895133
ROEMHELD18931466
ROEMHELD1942002
ROEMHELD1546165
ROEMHELD9284036
ROEMHELD6852-349
ROEMHELDNR.1896303VMH36，B1.880， levorotation
ROEMHELD9284036
ROEMHELD824030500
ROEMHELD1543165
ROEMHELD1543516
ROEMHELD1893N30L12DH
ROEMHELD1893N30R12DH
DYNISCO14804100 SERIAL:711448290 014，220VACpressure controller
DYNISCOART.- NR. 1480-4-1-0-0pressure controller
DYNISCOPT4624
DYNISCOPT4634-5M-12-SIL2
DYNISCOMDA422-1/2-3.5C-23/46-GC8pressure sensor
DYNISCOPT4624
DYNISCOPT4624-35MPA-6/16-SIL2pressure sensor
DYNISCOTPT4634-1/2-5M-12/18-SIL2
DYNISCO14802101 SERIAL:657282010 007，24VDCpressure controller
DYNISCOART.- NR. 1480-2-1-0-1pressure controller
DYNISCOPT4624-5M-25/18pressure sensor
DYNISCOPT4624-15M-12-SIL2
DYNISCOART.- NR. 1480-4-1-0-0
DYNISCOPT4624-35MPA-6/16-SIL2
DYNISCOPT4624-1/2-15M-12/18-SIL2
DYNISCOPT462E-5M-6/18
DYNISCOPT4626-1/2-3M-18/18sensor
DYNISCOTYP PT462E ART. -NR. : PT462E-5M-6/18
DYNISCOART.- NR. 1480-1-0-0-0
DYNISCOART.- NR. SPX 4622-N-A-05-B-21-DP-DD-A-AF-ZZ-GC9
DYNISCOTPT463F-1/2-5M-12/18-S137-SIL2pressure sensor
DYNISCOSPX2242-S-A-00-M-22-CE-FF-BCA-ZZ-B171 Check the model, which is 500BAR. After that, it says 20MPA=200BAR. What exactly do you need
DYNISCOMDT422F-1/2-1C-15/46-B171-GC0pressure sensor
DYNISCOMDT422F-1/2-3.5C-15/46-B171-GC8pressure sensor
DYNISCOART. - NR. TPT4634-1/2-50MPA-6/18-SIL2 This quantity is validsensor
DYNISCOPT462E-35MPA-6/18
DYNISCOART.- NR. SPX 4222-N-A-00-B-21-CE-DD-A-AF-ZZ-GC9
DYNISCOPT4626-1/2-5M-6/18
DYNISCOTPT4634-1/2-3M-12/18-SIL2
DYNISCO1480pressure gauge
DYNISCOPT4624-1/2-5M-6/18-SIL2pressure sensor
DYNISCOPT4626-1/2-5M-6/18
DYNISCO2242NAOOM21HTAABCAZZB628
DYNISCOPT4626-1/2-5M-12/18pressure sensor
DYNISCOReplace 1490
DYNISCOSPX 2291EA 56M 13DPDDACAZZPressure transmitter
DYNISCOMDA462-1/2-3,5C-15/46pressure sensor
DYNISCOMDT460F-M18-1M-15-SIL2Fusion pressure sensor
DYNISCO200100
DYNISCO14804100pressure gauge
DYNISCO1480-4-1-0-0pressure gauge
DYNISCO14804101display table
DYNISCOMDT422F-1/2-2C-15/46-B171-GC0pressure sensor
DYNISCOMDT460F-M18-1M-15-SIL2Fusion pressure sensor
DYNISCO200925
DYNISCO1480-4-1-0-1display table
DYNISCOMDT462L-M18-7C-15/46
DYNISCODYMT-S-1/2-J-5-10-G-2M-F13
DYNISCOECHO-MV3-MPA-R21-UNF-6PN-S06-F18-NTR
DYNISCODYMT-S-1/2-2XJ-5-10-G
DYNISCO1480-4-1-0-1 discounted price for contracts already madedisplay table
DYNISCOPT462E-1/2-5M-6/18sensor
DYNISCOMDA462-1/2-3,5C-15/46pressure sensor
DYNISCOTPT4634-35MPA-12/18-S147-SIL2sensor
DYNISCOPT462E-3.5CB-6/18-GC8
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2 replacementsensor
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTRsensor
DYNISCO1480-4-1-0-1display table
DYNISCODYMT-F-1/2-PT100/3-0-15-G-Htemperature sensor
DYNISCOPT4624-1/2-20MPA-6/18-SIL2
DYNISCOMDT422F-1/2-2C-15/46-SIL2 replacementsensor
DYNISCO1480-4-1-0-0 is valid for the entire orderpressure gauge
DYNISCOPT390-0-15M-A191
DYNISCOMDT462FH-1/2-2C-15/46-SIL2 replacementpressure sensor
DYNISCOPT4626-M18-7CB-6/18
DYNISCOECHO-MV3-BAR-R20-UNF-6PN-S06-F18-NTR 200BAR
DYNISCODYMT-S-1/2-2XJ-5-10-G-F13
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2
DYNISCOVT460-10sensor wire
DYNISCOPT4626-M18-7CB-6/18
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR 350BAR
DYNISCODYMT-S-1/2-PT100/4-15-15-G
DYNISCOMDT420F-1/2-5C-32-SIL2pressure sensor
DYNISCOECHO-VT1-BAR-R21-UNF-6PN-S06-F18-NTR 替代
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR replacement
DYNISCOSPX 2242 at 00 m 21 ceffbcazzb 106
DYNISCOTPT4636-1/2-35MPA-6/18
DYNISCOTPT4636-1/2-10M-9/18-SIL2
DYNISCOPT462E-1/2-5M-6/18
DYNISCO4012228cable
DYNISCOMDT462F-1/2-1C-15/46-SIL2
DYNISCOIDA353-5C-10V-D21
DYNISCO1480-4-1-0-0 substitution
DYNISCOM14-70MPA-6/18
DYNISCOMDT462F-1/2-3,5C-15/46-GC8pressure sensor
DYNISCO14834100
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2
DYNISCO14834100
DYNISCO14804100
DYNISCODYMT-F-1/2-PT100/3-0-15-G-H
DYNISCO14804100
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR replacementpressure sensor
DYNISCO2281-N-G-G-AC-5-P-19-A
DYNISCO4622-N-A-05-B-21-FE-DD-A-AF-ZZ-GC8
DYNISCOATC99040011
DYNISCOMDT462F-M18-7C-15/46-SIL2 replacement
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR
DYNISCO4622-N-A-05-B-21-FE-DD-A-AF-ZZ-GC8
DYNISCOMDT462F-1/2-7C-15/46
DYNISCOSPX2243-E-A-25-K-22-FE-FF-A-CA-ZZ-B171
DYNISCOMDT462L-M18-7C-15/46
DYNISCOIDA353-5C-10V-D21
DYNISCO1480-4-1-0-1
DYNISCO1480-4-1-0-0
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR
DYNISCOTPT4634-5M-15/18-SIL2
DYNISCOIDA353-7C-10V
DYNISCO14901
DYNISCO1480-4-1-0-1
DYNISCO1480-4-1-0-0pressure gauge
DYNISCO149041000
DYNISCOD7100 IDA353-3.5C
DYNISCO9966-7914
DYNISCOMDT462F-1/2-5C-23/46-B171-SIL2pressure sensor
DYNISCO1480-4-1-0-0
DYNISCODYKE-1/2-PT100/4-15-32-G-F14
DYNISCO1A422-1/2-3.5C-23/46-GC8/000ST
DYNISCOMDT462F-1/2-5C-15/46-B171-SIL2pressure sensor
ROEMHELD1891201
ROEMHELD1942000
ROEMHELD1895609
ROEMHELD0460831
ROEMHELD1283005
ROEMHELD1296120250
ROEMHELD1544165+0131156
ROEMHELD1545160L
ROEMHELD1895141M
ROEMHELD1896303VDH36
ROEMHELD2951417
ROEMHELD1895509
ROEMHELD9384006
ROEMHELD811968012
ROMHELD0132703
ROEMHELD0460656
ROEMHELD04601020
ROEMHELD1829743D00
ROEMHELD1850102M
ROEMHELD1895624M
ROEMHELD1829740D00
ROEMHELD1845L090L30M
ROMHELD9281136
ROEMHELD9281136
ROMHELD811968011
ROMHELD9384755
ROEMHELD0132732
ROMHELD9281-136
ROEMHELD3412044
ROMHELD9384735
ROEMHELD1895323
ROEMHELD1895503
ROEMHELD1942925
ROEMHELD4412974
ROEMHELD1942410P
ROEMHELD1547176
ROEMHELD1547210
ROEMHELD8755020
HELDHAIN555541-01
ROEMHELD1543105S
ROEMHELD1463101
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD1891121
ROEMHELD1801200
ROEMHELD1802200
ROEMHELD1463610
ROEMHELD1895604
ROEMHELD1895504
ROEMHELD1895604
FROEMHELD1942112
ROEMHELD804474
ROEMHELD704201
ROEMHELD1942201
ROMHELD1541105S
ROMHELD1545105S
ROEMHELD1875303
ROEMHELD1875403
ROMHELD1550196
ROMHELD3614070
ROMHELD1543523
ROMHELD1738-858
ROEMHELD9284036
ROEMHELD1896303VMH36
ROEMHELD4312151
ROEMHELD3829-234
ROEMHELD1547-513 is valid for the entire order
ROEMHELD1547-516
ROEMHELD3829-234
ROEMHELD3829-099
ROEMHELD3829234
ROEMHELD1547516
ROEMHELD0132478 1844-A0XXX24(M)
ROEMHELD0132689
ROEMHELD1942002
ROEMHELD1875303
ROEMHELD1875403
ROEMHELD1545105
ROEMHELD1543407
ROEMHELDPOINTS FOR 1843847
ROEMHELD3821246
ROEMHELD1543265
ROEMHELD1804230
ROEMHELD1942007
ROEMHELD1344165
ROEMHELD4317200
ROEMHELD8459001
ROEMHELD8145160
ROEMHELD1955932
ROEMHELD1472001
ROEMHELD1543101
ROMHELD8.2135.2820
ROEMHELD1471011M
ROEMHELDAlternative: 1824828A
ROEMHELD500071-
ROEMHELD500071
ROEMHELD1893504
ROEMHELD1893604
ROEMHELD1513020
ROEMHELD1955012
ROEMHELD120034
ROEMHELD70580
ROEMHELD199948
ROEMHELD196207
ROEMHELD1846A090R36
ROEMHELD1121987-00
ROEMHELD1846A090R36
ROEMHELD1846A090L36
ROEMHELD9208181
ROEMHELDARTICLE NO. 0460682
ROEMHELDS03642
ROEMHELDS03928
ROEMHELDS04156
ROEMHELDEEPDRDS3-05-115-5-24V
ROEMHELD1534136B
ROEMHELD3829228
ROEMHELD1533166
ROEMHELD3829228
ROEMHELD1534136B
ROEMHELD1533166
ROEMHELD1548105BH10
ROEMHELD1535196B
ROEMHELD1547106B
ROEMHELD1534166B
ROEMHELD1544165B
ROEMHELD1533166
ROEMHELD3829228 M12X1 MM
ROEMHELD1544105
ROEMHELD1544105B
ROEMHELD1533166
ROEMHELD1533166
ROEMHELD3829-228-M12
ROEMHELD3829228
ROEMHELD1533166
ROEMHELD1533166
ROEMHELD1534136B
ROEMHELD3829228
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD1534136B
ROEMHELD1533166
ROEMHELD0460836
ROEMHELD3829228
ROMHELD1897-275
ROEMHELD1533166
ROEMHELD29453
ROMHELD1464610
ROMHELD1543513
ROMHELD1544513
ROMHELD1544516
ROMHELD1895104
ROEMHELD1461110
ROEMHELD1803230
ROEMHELD1547110
ROEMHELD0460831
ROEMHELD18931191VI
ROEMHELD1895103
ROEMHELD15431144 is valid for the entire order
ROEMHELD15431140
ROEMHELD1803131B
ROEMHELD1579856
ROEMHELD804-474
ROEMHELD804 474
ROEMHELD0460730
ROEMHELD300199
ROEMHELD3001999
ROEMHELD1845N075L43M
ROEHMHELD1543265
ROEMHELD1893303
ROEMHELD1845F090L30
ROEMHELD1844F090R24
ROEMHELD1942010
ROEMHELD18911024
ROEMHELD1545210
ROEMHELD1296100450
ROEMHELD1297100500
ROEMHELD3829234
ROEMHELD3829099
ROEMHELD3829-234
ROEMHELD1546195 is valid for the entire order
ROEMHELD1547516B
ROEMHELD1824510A
ROEMHELD1461110
ROEMHELD1804230
ROEMHELD2954-429
ROEMHELD1804-121
ROEMHELD189-101M
ROEMHELD0460937
ROEMHELD2951416
ROEMHELDDiscontinued production to replace 2954620. The external dimensions are slightly smaller, but the connection dimensions are the same.
ROEMHELD102913-03
ROEMHELD146
ROEMHELD1942012
ROEMHELD1458002
ROEMHELD0132566
ROEMHELD1953858
ROEMHELD1941820
ROEMHELD1942-017
ROEMHELD1942010
ROEMHELD1942012
ROEMHELD1942017
ROEMHELD1953858
ROEMHELD1942010
ROEMHELD1458005
ROEMHELD1942017
ROEMHELD1458002
ROEMHELD1942117
ROEMHELD1942017
ROEMHELD3709012
ROEMHELD1942112
ROEMHELD1941-820
ROEMHELD1942010
ROEMHELD3707021
ROEMHELD3710081
ROEMHELD0132466 +1953858
ROEMHELD1546-210
ROEMHELD1458-002
ROEMHELD3610246
ROEMHELD9210-145
ROEMHELD1897208VMH38
ROEMHELD132125
ROEMHELD1942112
ROEMHELD5700013
ROEMHELD18951330M90
ROEMHELD1895133
ROEMHELD1824809A
ROEMHELD1546429L
ROEMHELD1551885
ROEMHELD1550939
ROEMHELD0132071 DICHTSATZ FKM FOR 1550-1X1
ROEMHELD1545105H10
ROEMHELD1471011
ROEMHELD1935802
ROEMHELD1933808
ROEMHELD1290288
ROEMHELD1290285
ROEMHELD1297130120
ROMHELD2954-429
ROMHELD1458-002
ROMHELDRPF 12-5
ROMHELD1942-000
ROEMHELD1942000
ROEMHELD1458002
ROEMHELD2954429
ROEMHELDRPF 12-5
ROEMHELD1885-104
ROEMHELD1545165
ROEMHELD1804-110
ROEMHELD1804-110
ROEMHELD1804130
ROEMHELD1534166
ROEMHELD575
ROEMHELD575
ROEMHELD4605932
ROEMHELD1953022
ROEMHELD1942925
ROEMHELD4412974
ROEMHELD1458001
ROEMHELD1942410P
ROMHELD1953022
ROMHELD1942925
ROMHELD4412974
ROMHELD0132384
ROEMHELD1854Q090R21M
ROEMHELD8804006
ROEMHELD3614075
ROEMHELDBS4253RB075N1
ROEMHELD9425-102
The cabbage fields on both sides of Lao Zhang's north and south are divided into three parts each. Lao Zhang hopes to obtain a small portion of water flow from the main waterway through a one-time waterway modification, with the water flow velocity as similar as possible to other fields, as shown in Figure 1. In this way, Lao Zhang can rest under the shade of trees for a while without making any changes to the waterway, and all the land can be watered at the same time.
A coupler is a radio frequency device that extracts a small portion of the signal from the wireless signal backbone channel, as shown in Figure 2. Like a power divider, it is a power distribution device, but the coupler is an unequal power distribution device. The combination of couplers and power dividers is mainly used to achieve a goal - to evenly distribute the transmission power of the signal source to each antenna port of the indoor distribution system, so that the transmission power of each antenna port is basically the same.
The input port power of an ideal coupler is equal to the sum of the coupling port power and the output port power, measured in watts (W)
As shown in Figure 3.
The important indicators of a coupler are coupling degree and insertion loss. The coupling degree is the ratio of the power between the coupling port and the input port, which is generally negative in dB. The larger the absolute value of the coupling degree, the less things are taken away, and the lower the loss of the natural coupler. Insertion loss is the ratio of power between the output port and the input port. The larger the absolute value of coupling degree, the smaller the absolute value of insertion loss.
If expressed in dB, there is the following relationship:
So, the relationship between the insertion loss (dB) and coupling degree (dB) of the coupler can be expressed as:
example:
A coupler with a coupling degree of -10dB has an insertion loss of -0.5dB. Taking the absolute value and considering the dielectric loss, the insertion loss is generally larger and varies from manufacturer to manufacturer. Generally, the insertion loss can be around 0.7dB.
If the input port power is 15dBm, then the power of the coupling port of this coupler is 15dBm-10dB=5dBm, and the power of the output port is 15dBm-0.7dB=14.3dBm.
Many people may ask this question: why is energy not conserved when 5dBm+14.3dmm>15dBm? The reason is simple, quantities in dBm cannot be added together.
Applying an electrical signal to the input of the optocoupler causes the light source to emit light, and the intensity of the light depends on the magnitude of the excitation current. After this light is irradiated onto the packaged photodetector, a photocurrent is generated due to the photoelectric effect, which is led out from the output of the photodetector, thus achieving the conversion of electricity to light to electricity.
1. Working Characteristics (Taking Phototransistor as an Example)
The common mode rejection ratio inside the optocoupler is very high. Because the coupling capacitance between the light-emitting tube and the receiver is very small (within 2pF), the common mode input voltage has little effect on the output current through the inter electrode coupling capacitance, resulting in a high common mode rejection ratio.
2. Output characteristics
The output characteristics of a optocoupler refer to the relationship between the bias voltage VCE applied to the photosensitive tube and the output current IC at a certain emission current IF. When IF=0, the light-emitting diode does not emit light, and the collector output current of the photosensitive transistor at this time is called dark current, which is generally very small. When IF>0, under a certain IF effect, the corresponding IC is basically independent of VCE. The variation between IC and IF is linearly related, and the output characteristics of the optocoupler measured by a semiconductor transistor characteristic diagram instrument are similar to those of a conventional transistor.
3. Optocouplers can be used as linear couplers
Provide a bias current on the light-emitting diode, and then couple the signal voltage to the light-emitting diode through a resistor. This way, the phototransistor receives a light signal that increases or decreases in the bias current, and its output current will vary linearly with the input signal voltage. Optocouplers can also operate in a switch state to transmit pulse signals. When transmitting pulse signals, there is a certain delay time between the input signal and the output signal, and the input and output delay times of optocouplers with different structures vary greatly.
Optoelectronic testing
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1. Use a multimeter to determine the quality, as shown in Figure 3. Disconnect the input power supply and measure the resistance of pins 1 and 2 using the R × 1k gear. The forward resistance should be several hundred ohms, the reverse resistance should be several tens of thousands of ohms, and the resistance between pins 3 and 4 should be infinite. 1. Any group between pin 2 and pins 3 and 4 has an infinite resistance value. After the input terminal is powered on, the resistance of pins 3 and 4 is very small. Adjusting the resistance between pins 3 and 4 of RP indicates that the device is functioning properly. Note: The R × 10k gear cannot be used, otherwise it may cause breakdown of the transmission tube.
2. Simple testing circuit: When the power is turned on, the LED does not light up. Pressing SB will make the LED light up. Adjusting the RP and LED light intensity will change, indicating that the tested optocoupler is good.
application
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1. Composition of switch circuit
When the input signal ui is at a low level, transistor V1 is in an off state, and the current of the light-emitting diode in optocoupler B1 is approximately zero. The resistance between output terminals Q11 and Q12 is very high, which is equivalent to the switch being "disconnected"; When UI is at high level, v1 conducts and the light-emitting diode in B1 emits light. The resistance between Q11 and Q12 decreases, which is equivalent to the switch being "turned on". This circuit is in a high-level conducting state because Ui is at low level and the switch is not connected. Similarly, when there is no signal (Ui is at low level), the switch conducts, so it is in a low-level conducting state
2. Composition of Logic Circuits
The circuit is an AND gate logic circuit. The logical expression is P=A.B. In the figure, two phototransistors are connected in series. Only when the input logic levels A=1 and B=1, the output P=1. Similarly, logic circuits such as "OR gate", "NAND gate", and "OR NOT gate" can also be formed
3. Form an isolated coupling circuit
The circuit is shown in Figure 4. This is a typical AC coupled amplifier circuit. By appropriately selecting the current limiting resistor Rl of the light-emitting circuit, the current transfer ratio of B4 can be kept constant to ensure the linear amplification effect of the circuit.
4. Form a high-voltage voltage regulator circuit
The driving transistor needs to use a transistor with high voltage resistance (the driving transistor in the figure is 3DG27). When the output voltage increases, the bias voltage of V55 increases, and the forward current of the light-emitting diode in B5 increases, causing the inter electrode voltage of the photosensitive tube to decrease. The bias voltage of the junction of the tube is adjusted to decrease while the internal resistance increases, resulting in a decrease in the output voltage while maintaining its stability
5. Assemble the automatic control circuit for the lobby lighting
A is four sets of analog electronic switches (S1~S4): S1, S2, S3 are connected in parallel (to increase driving power and anti-interference ability) for the delay circuit. When it is powered on, R4 and B6 drive the bidirectional thyristor VT, which directly controls the hall lighting H; S4 and external photoresistor Rl form an environmental light detection circuit. When the door is closed, the normally closed reed switch KD installed on the door frame is subjected to the action of the magnet on the door, and its contacts are disconnected, with S1, S2, and S3 in the data open state. At night, when the host returns home and opens the door, the magnet moves away from KD and the KD contact closes. At this time, the 9V power supply is rectified and charged to C1 through R1. The voltage at both ends of C1 quickly rises to 9V. The rectified voltage, through S1, S2, S3, and R4, causes the light-emitting tube in B6 to emit light, triggering the bidirectional thyristor to conduct. VT also conducts, and H lights up, achieving automatic lighting control. After the door is closed, the magnet controls KD, the contacts are disconnected, the 9V power supply stops charging C1, and the circuit enters a delay state. C1 begins to discharge R3, and after a delay, the voltage at both ends of C1 gradually drops below the turn-on voltage (1.5v) of S1, S2, and S3. S1, S2, and S3 return to the disconnected state, causing B6 to turn off, VT to turn off, and H to turn off, achieving the delayed light off function.
Distinguish types
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Directional type
A directional coupler is a four port component with directional transmission characteristics, consisting of two pairs of transmission systems connected by coupling devices. Firstly, introduce the performance indicators of directional couplers, followed by waveguide dual hole directional couplers, dual branch directional couplers, and parallel coupled microstrip directional couplers.
1) Performance indicators of directional couplers
A directional coupler is a four port network, with port "①" as the input terminal, port "②" as the direct output terminal, port "③" as the coupled output terminal, and port "④" as the isolation terminal. Its scattering matrix is set to [S]. The performance indicators of a directional coupler include coupling degree, isolation degree, orientation degree, input standing wave ratio, and operating bandwidth. Please introduce them separately below.
2) Isolation degree
The ratio of the input power P1 of input terminal "①" to the output power P4 of isolation terminal "④" is defined as the isolation degree, denoted as I.
⑶ Orientation degree
The ratio of the output power P3 of the coupling end "③" to the output power P4 of the isolation end "④" is defined as directionality, denoted as D.
⑷ Input standing wave ratio
The standing wave ratio of input port ① when ports ②, ③, and ④ are all connected to matching loads is defined as the input standing wave ratio, denoted as ρ.
⑸ Working bandwidth
The working bandwidth refers to the frequency range within which the parameters C, I, D, and ρ of the directional coupler meet the requirements.
Types of waveguides
The waveguide dual hole directional coupler is a waveguide directional coupler, in which the main and auxiliary waveguides pass through two common narrow walls
A small hole with a distance of d=(2n+1) λ g0/4 is used to achieve coupling, where λ g0 is the waveguide wavelength corresponding to the center frequency and n is a positive integer, generally taken as n=0. The coupling hole is generally circular, but can also be of other shapes. When working at the center frequency, β d=π/2, at which point D →∞; When deviating from the center frequency, sec β d has a certain value, at which point D is no longer infinite. In fact, even at the center frequency, the directionality of the dual hole coupler is not infinite, but can only be around 30dB.
In short, the waveguide dual hole directional coupler relies on the mutual interference of waves to achieve directional output of the main waveguide, with in-phase superposition at the coupling port and inverse cancellation at the isolation port. In order to increase the coupling degree of the directional coupler and broaden the operating frequency band, a porous directional coupler can be used,
Double classification types
The dual branch directional coupler consists of a main line, a secondary line, and two branch lines, where the branch line
The length and spacing are both 1/4 of the center wavelength, as shown in Figure 5-15. The characteristic impedance of the main entrance line "①" is, the characteristic impedance of the main exit line "②" is (k is the impedance transformation ratio), the characteristic impedance of the isolation end "④" of the secondary line is, the characteristic impedance of the coupling end "③" of the secondary line is, the characteristic impedance of the parallel connection line is Z0p, and the characteristic impedances of the two branch lines are and, respectively.
Parallel types
Parallel coupled microstrip directional coupler is a type of reverse directional coupler, with its coupled output end on the same side as the main input end, as shown in the figure on the right. Port in is the input port, port out is the through port, port Ocap is the coupling port, and port "④" is the isolation port.
Technical specifications for couplers (indoor distribution)
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Table 2 Technical specifications of couplers
project
specification
5dB
7dB
10dB
15dB
20dB
insertion loss
≤1.7dB
≤1.2dB
≤0.7dB
≤0.3dB
≤0.3dB
VSW standing wave ratio
≤1.4
Coupling loss
5dB
7dB
10dB
15dB
20dB
Maximum input power
15W
Type of connector (interface)
N-Female
isolator
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Isolators, also known as inverters, experience almost no attenuation when electromagnetic waves pass through them in the forward direction, but significant attenuation when they pass through them in the reverse direction. Common isolators include harmonic isolators
There are two types: vibration type and field displacement type.
Resonant isolator
Due to the anisotropy of ferrite, under a constant magnetic field Hi, the left and right circularly polarized rotating magnetic fields that form a left and right spiral relationship with the Hi direction have different permeabilities (denoted as μ - and μ+, respectively). At a certain point on a microwave transmission line containing ferrite materials, a left-handed magnetic field is transmitted along the+z direction, and a right-handed magnetic field is transmitted along the - z direction. The two transmit the same distance, but the corresponding magnetic permeability is different. Therefore, the phase velocities of the left-handed and right-handed magnetic fields are different, resulting in different phase shifts. This is the irreversibility of ferrite phase shifts. On the other hand, ferrite exhibits ferromagnetic resonance effect and resonant absorption effect of circularly polarized magnetic field.
The so-called ferromagnetic resonance effect of ferrite refers to the maximum absorption of microwave energy by ferrite when the operating frequency ω of the magnetic field is equal to the resonant angular frequency ω 0 of ferrite. For circularly polarized magnetic fields, left and right polarized magnetic fields have different magnetic permeabilities, resulting in different absorption characteristics for both.
For a right-handed polarized magnetic field with a magnetic permeability of μ+in reverse transmission, it exhibits ferromagnetic resonance effect, while for a left-handed polarized magnetic field with a magnetic permeability of μ - in forward transmission, it does not exhibit ferromagnetic resonance characteristics, which is the resonance effect of a circularly polarized magnetic field. The ferrite resonant isolator is made by utilizing this characteristic of ferrite.
Field moving isolator
Field shift isolators are made based on the different field shift effects of ferrite on the wave modes transmitted in two directions.
It adds attenuation plates on the side of the ferrite sheet, and due to the different deviations of the fields generated by the two directions of transmission, the electric field of the wave transmitted in the forward direction (- z direction) is biased towards the side without attenuation plates, while the electric field of the wave transmitted in the reverse direction (+z direction) is biased towards the side of attenuation plates, thus achieving the isolation function of small forward attenuation and large reverse attenuation, as shown in Figure 5-32.
Due to its small size, light weight, simple structure, and wide operating frequency band, field moving isolators have been widely used in low-power applications
The cabbage fields on both sides of Lao Zhang's north and south are divided into three parts each. Lao Zhang hopes to obtain a small portion of water flow from the main waterway through a one-time waterway modification, with the water flow velocity as similar as possible to other fields, as shown in Figure 1. In this way, Lao Zhang can rest under the shade of trees for a while without making any changes to the waterway, and all the land can be watered at the same time.
A coupler is a radio frequency device that extracts a small portion of the signal from the wireless signal backbone channel, as shown in Figure 2. Like a power divider, it is a power distribution device, but the coupler is an unequal power distribution device. The combination of couplers and power dividers is mainly used to achieve a goal - to evenly distribute the transmission power of the signal source to each antenna port of the indoor distribution system, so that the transmission power of each antenna port is basically the same.
The input port power of an ideal coupler is equal to the sum of the coupling port power and the output port power, measured in watts (W)
As shown in Figure 3.
The important indicators of a coupler are coupling degree and insertion loss. The coupling degree is the ratio of the power between the coupling port and the input port, which is generally negative in dB. The larger the absolute value of the coupling degree, the less things are taken away, and the lower the loss of the natural coupler. Insertion loss is the ratio of power between the output port and the input port. The larger the absolute value of coupling degree, the smaller the absolute value of insertion loss.
If expressed in dB, there is the following relationship:
So, the relationship between the insertion loss (dB) and coupling degree (dB) of the coupler can be expressed as:
example:
A coupler with a coupling degree of -10dB has an insertion loss of -0.5dB. Taking the absolute value and considering the dielectric loss, the insertion loss is generally larger and varies from manufacturer to manufacturer. Generally, the insertion loss can be around 0.7dB.
If the input port power is 15dBm, then the power of the coupling port of this coupler is 15dBm-10dB=5dBm, and the power of the output port is 15dBm-0.7dB=14.3dBm.
Many people may ask this question: why is energy not conserved when 5dBm+14.3dmm>15dBm? The reason is simple, quantities in dBm cannot be added together.
Applying an electrical signal to the input of the optocoupler causes the light source to emit light, and the intensity of the light depends on the magnitude of the excitation current. After this light is irradiated onto the packaged photodetector, a photocurrent is generated due to the photoelectric effect, which is led out from the output of the photodetector, thus achieving the conversion of electricity to light to electricity.
1. Working Characteristics (Taking Phototransistor as an Example)
The common mode rejection ratio inside the optocoupler is very high. Because the coupling capacitance between the light-emitting tube and the receiver is very small (within 2pF), the common mode input voltage has little effect on the output current through the inter electrode coupling capacitance, resulting in a high common mode rejection ratio.
2. Output characteristics
The output characteristics of a optocoupler refer to the relationship between the bias voltage VCE applied to the photosensitive tube and the output current IC at a certain emission current IF. When IF=0, the light-emitting diode does not emit light, and the collector output current of the photosensitive transistor at this time is called dark current, which is generally very small. When IF>0, under a certain IF effect, the corresponding IC is basically independent of VCE. The variation between IC and IF is linearly related, and the output characteristics of the optocoupler measured by a semiconductor transistor characteristic diagram instrument are similar to those of a conventional transistor.
3. Optocouplers can be used as linear couplers
Provide a bias current on the light-emitting diode, and then couple the signal voltage to the light-emitting diode through a resistor. This way, the phototransistor receives a light signal that increases or decreases in the bias current, and its output current will vary linearly with the input signal voltage. Optocouplers can also operate in a switch state to transmit pulse signals. When transmitting pulse signals, there is a certain delay time between the input signal and the output signal, and the input and output delay times of optocouplers with different structures vary greatly.
Optoelectronic testing
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1. Use a multimeter to determine the quality, as shown in Figure 3. Disconnect the input power supply and measure the resistance of pins 1 and 2 using the R × 1k gear. The forward resistance should be several hundred ohms, the reverse resistance should be several tens of thousands of ohms, and the resistance between pins 3 and 4 should be infinite. 1. Any group between pin 2 and pins 3 and 4 has an infinite resistance value. After the input terminal is powered on, the resistance of pins 3 and 4 is very small. Adjusting the resistance between pins 3 and 4 of RP indicates that the device is functioning properly. Note: The R × 10k gear cannot be used, otherwise it may cause breakdown of the transmission tube.
2. Simple testing circuit: When the power is turned on, the LED does not light up. Pressing SB will make the LED light up. Adjusting the RP and LED light intensity will change, indicating that the tested optocoupler is good.
application
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1. Composition of switch circuit
When the input signal ui is at a low level, transistor V1 is in an off state, and the current of the light-emitting diode in optocoupler B1 is approximately zero. The resistance between output terminals Q11 and Q12 is very high, which is equivalent to the switch being "disconnected"; When UI is at high level, v1 conducts and the light-emitting diode in B1 emits light. The resistance between Q11 and Q12 decreases, which is equivalent to the switch being "turned on". This circuit is in a high-level conducting state because Ui is at low level and the switch is not connected. Similarly, when there is no signal (Ui is at low level), the switch conducts, so it is in a low-level conducting state
2. Composition of Logic Circuits
The circuit is an AND gate logic circuit. The logical expression is P=A.B. In the figure, two phototransistors are connected in series. Only when the input logic levels A=1 and B=1, the output P=1. Similarly, logic circuits such as "OR gate", "NAND gate", and "OR NOT gate" can also be formed
3. Form an isolated coupling circuit
The circuit is shown in Figure 4. This is a typical AC coupled amplifier circuit. By appropriately selecting the current limiting resistor Rl of the light-emitting circuit, the current transfer ratio of B4 can be kept constant to ensure the linear amplification effect of the circuit.
4. Form a high-voltage voltage regulator circuit
The driving transistor needs to use a transistor with high voltage resistance (the driving transistor in the figure is 3DG27). When the output voltage increases, the bias voltage of V55 increases, and the forward current of the light-emitting diode in B5 increases, causing the inter electrode voltage of the photosensitive tube to decrease. The bias voltage of the junction of the tube is adjusted to decrease while the internal resistance increases, resulting in a decrease in the output voltage while maintaining its stability
5. Assemble the automatic control circuit for the lobby lighting
A is four sets of analog electronic switches (S1~S4): S1, S2, S3 are connected in parallel (to increase driving power and anti-interference ability) for the delay circuit. When it is powered on, R4 and B6 drive the bidirectional thyristor VT, which directly controls the hall lighting H; S4 and external photoresistor Rl form an environmental light detection circuit. When the door is closed, the normally closed reed switch KD installed on the door frame is subjected to the action of the magnet on the door, and its contacts are disconnected, with S1, S2, and S3 in the data open state. At night, when the host returns home and opens the door, the magnet moves away from KD and the KD contact closes. At this time, the 9V power supply is rectified and charged to C1 through R1. The voltage at both ends of C1 quickly rises to 9V. The rectified voltage, through S1, S2, S3, and R4, causes the light-emitting tube in B6 to emit light, triggering the bidirectional thyristor to conduct. VT also conducts, and H lights up, achieving automatic lighting control. After the door is closed, the magnet controls KD, the contacts are disconnected, the 9V power supply stops charging C1, and the circuit enters a delay state. C1 begins to discharge R3, and after a delay, the voltage at both ends of C1 gradually drops below the turn-on voltage (1.5v) of S1, S2, and S3. S1, S2, and S3 return to the disconnected state, causing B6 to turn off, VT to turn off, and H to turn off, achieving the delayed light off function.
Distinguish types
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edit
Directional type
A directional coupler is a four port component with directional transmission characteristics, consisting of two pairs of transmission systems connected by coupling devices. Firstly, introduce the performance indicators of directional couplers, followed by waveguide dual hole directional couplers, dual branch directional couplers, and parallel coupled microstrip directional couplers.
1) Performance indicators of directional couplers
A directional coupler is a four port network, with port "①" as the input terminal, port "②" as the direct output terminal, port "③" as the coupled output terminal, and port "④" as the isolation terminal. Its scattering matrix is set to [S]. The performance indicators of a directional coupler include coupling degree, isolation degree, orientation degree, input standing wave ratio, and operating bandwidth. Please introduce them separately below.
2) Isolation degree
The ratio of the input power P1 of input terminal "①" to the output power P4 of isolation terminal "④" is defined as the isolation degree, denoted as I.
⑶ Orientation degree
The ratio of the output power P3 of the coupling end "③" to the output power P4 of the isolation end "④" is defined as directionality, denoted as D.
⑷ Input standing wave ratio
The standing wave ratio of input port ① when ports ②, ③, and ④ are all connected to matching loads is defined as the input standing wave ratio, denoted as ρ.
⑸ Working bandwidth
The working bandwidth refers to the frequency range within which the parameters C, I, D, and ρ of the directional coupler meet the requirements.
Types of waveguides
The waveguide dual hole directional coupler is a waveguide directional coupler, in which the main and auxiliary waveguides pass through two common narrow walls
A small hole with a distance of d=(2n+1) λ g0/4 is used to achieve coupling, where λ g0 is the waveguide wavelength corresponding to the center frequency and n is a positive integer, generally taken as n=0. The coupling hole is generally circular, but can also be of other shapes. When working at the center frequency, β d=π/2, at which point D →∞; When deviating from the center frequency, sec β d has a certain value, at which point D is no longer infinite. In fact, even at the center frequency, the directionality of the dual hole coupler is not infinite, but can only be around 30dB.
In short, the waveguide dual hole directional coupler relies on the mutual interference of waves to achieve directional output of the main waveguide, with in-phase superposition at the coupling port and inverse cancellation at the isolation port. In order to increase the coupling degree of the directional coupler and broaden the operating frequency band, a porous directional coupler can be used,
Double classification types
The dual branch directional coupler consists of a main line, a secondary line, and two branch lines, where the branch line
The length and spacing are both 1/4 of the center wavelength, as shown in Figure 5-15. The characteristic impedance of the main entrance line "①" is, the characteristic impedance of the main exit line "②" is (k is the impedance transformation ratio), the characteristic impedance of the isolation end "④" of the secondary line is, the characteristic impedance of the coupling end "③" of the secondary line is, the characteristic impedance of the parallel connection line is Z0p, and the characteristic impedances of the two branch lines are and, respectively.
Parallel types
Parallel coupled microstrip directional coupler is a type of reverse directional coupler, with its coupled output end on the same side as the main input end, as shown in the figure on the right. Port in is the input port, port out is the through port, port Ocap is the coupling port, and port "④" is the isolation port.
Technical specifications for couplers (indoor distribution)
broadcast
edit
Table 2 Technical specifications of couplers
project
specification
5dB
7dB
10dB
15dB
20dB
insertion loss
≤1.7dB
≤1.2dB
≤0.7dB
≤0.3dB
≤0.3dB
VSW standing wave ratio
≤1.4
Coupling loss
5dB
7dB
10dB
15dB
20dB
Maximum input power
15W
Type of connector (interface)
N-Female
isolator
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edit
Isolators, also known as inverters, experience almost no attenuation when electromagnetic waves pass through them in the forward direction, but significant attenuation when they pass through them in the reverse direction. Common isolators include harmonic isolators
There are two types: vibration type and field displacement type.
Resonant isolator
Due to the anisotropy of ferrite, under a constant magnetic field Hi, the left and right circularly polarized rotating magnetic fields that form a left and right spiral relationship with the Hi direction have different permeabilities (denoted as μ - and μ+, respectively). At a certain point on a microwave transmission line containing ferrite materials, a left-handed magnetic field is transmitted along the+z direction, and a right-handed magnetic field is transmitted along the - z direction. The two transmit the same distance, but the corresponding magnetic permeability is different. Therefore, the phase velocities of the left-handed and right-handed magnetic fields are different, resulting in different phase shifts. This is the irreversibility of ferrite phase shifts. On the other hand, ferrite exhibits ferromagnetic resonance effect and resonant absorption effect of circularly polarized magnetic field.
The so-called ferromagnetic resonance effect of ferrite refers to the maximum absorption of microwave energy by ferrite when the operating frequency ω of the magnetic field is equal to the resonant angular frequency ω 0 of ferrite. For circularly polarized magnetic fields, left and right polarized magnetic fields have different magnetic permeabilities, resulting in different absorption characteristics for both.
For a right-handed polarized magnetic field with a magnetic permeability of μ+in reverse transmission, it exhibits ferromagnetic resonance effect, while for a left-handed polarized magnetic field with a magnetic permeability of μ - in forward transmission, it does not exhibit ferromagnetic resonance characteristics, which is the resonance effect of a circularly polarized magnetic field. The ferrite resonant isolator is made by utilizing this characteristic of ferrite.
Field moving isolator
Field shift isolators are made based on the different field shift effects of ferrite on the wave modes transmitted in two directions.
It adds attenuation plates on the side of the ferrite sheet, and due to the different deviations of the fields generated by the two directions of transmission, the electric field of the wave transmitted in the forward direction (- z direction) is biased towards the side without attenuation plates, while the electric field of the wave transmitted in the reverse direction (+z direction) is biased towards the side of attenuation plates, thus achieving the isolation function of small forward attenuation and large reverse attenuation, as shown in Figure 5-32.
Due to its small size, light weight, simple structure, and wide operating frequency band, field moving isolators have been widely used in low-power applications
ROEMHELD1800110
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ROEHMHELD0353814
ROEHMHELD0353354S
ROEMHELD1942501
ROEMHELD 1942501
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ROEMHELD3614396
ROEMHELD1947400
ROEMHELD3819076
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ROEMHELD1942-007
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ROMHELD1546
ROEMHELD1297-10-0400
ROEMHELD1297-10-0500
ROEMHELD1895639
ROEMHELD1942990
ROEMHELD1534196B is valid for the entire order. Please verify the model
ROEMHELD1534136B + 3829289
ROEMHELD1536-136B_HUB_25 SENSOR_3929-289
ROEMHELD1544195BH95
ROEMHELD471TC-12
ROEMHELD18961036P45M
ROEMHELD1541-106XM
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ROEMHELD1824510A
ROEMHELD15431140
ROEMHELD15431144
ROEMHELD15431144
ROEMHELD1895503
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ROEMHELD2954429
ROEMHELD2953100
ROEMHELD9284036
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ROEMHELD1535166B
ROEMHELD1547-265
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ROEMHELD1543-513
ROEMHELD1537-146B
ROEMHELD1535166B
ROEMHELD1534136B
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HELDHAIN555541-01
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FROEMHELD1942112
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ROMHELD1541105S
ROMHELD1545105S
ROEMHELD1875303
ROEMHELD1875403
ROMHELD1550196
ROMHELD3614070
ROMHELD1543523
ROMHELD1738-858
ROEMHELD9284036
ROEMHELD1896303VMH36
ROEMHELD4312151
ROEMHELD3829-234
ROEMHELD1547-513 is valid for the entire order
ROEMHELD1547-516
ROEMHELD3829-234
ROEMHELD3829-099
ROEMHELD3829234
ROEMHELD1547516
ROEMHELD0132478 1844-A0XXX24(M)
ROEMHELD0132689
ROEMHELD1942002
ROEMHELD1875303
ROEMHELD1875403
ROEMHELD1545105
ROEMHELD1543407
ROEMHELDPOINTS FOR 1843847
ROEMHELD3821246
ROEMHELD1543265
ROEMHELD1804230
ROEMHELD1942007
ROEMHELD1344165
ROEMHELD4317200
ROEMHELD8459001
ROEMHELD8145160
ROEMHELD1955932
ROEMHELD1472001
ROEMHELD1543101
ROMHELD8.2135.2820
ROEMHELD1471011M
ROEMHELDAlternative: 1824828A
ROEMHELD500071-
ROEMHELD500071
ROEMHELD1893504
ROEMHELD1893604
ROEMHELD1513020
ROEMHELD1955012
ROEMHELD120034
ROEMHELD70580
ROEMHELD199948
ROEMHELD196207
ROEMHELD1846A090R36
ROEMHELD1121987-00
ROEMHELD1846A090R36
ROEMHELD1846A090L36
ROEMHELD9208181
ROEMHELDARTICLE NO. 0460682
ROEMHELDS03642
ROEMHELDS03928
ROEMHELDS04156
ROEMHELDS03643
ROEMHELD1547175
ROEMHELD1549105
ROEMHELD1546165
ROEMHELD1297-10-0500
ROEMHELD1545210
ROEMHELD1545210
ROEMHELD1545210
ROEMHELD1294100110
ROEMHELD1545210
ROEMHELD1942300
ROEMHELD1545106
ROEMHELD1897204
ROEMHELD1955932
ROEMHELD1955932
ROEMHELD1895303VDH35
ROEMHELD1911022
ROEMHELD1434001
HELDENHAINAK ERM 280 1200 03S12-03
ROEMHELD1575105
ROEMHELD3890014
ROEMHELD1296940
ROEMHELD18951330M90
ROEMHELD1895133
ROEMHELD18931466
ROEMHELD1942002
ROEMHELD1546165
ROEMHELD9284036
ROEMHELD6852-349
ROEMHELDNR.1896303VMH36，B1.880， levorotation
ROEMHELD9284036
ROEMHELD824030500
ROEMHELD1543165
ROEMHELD1543516
ROEMHELD1893N30L12DH
ROEMHELD1893N30R12DH
DYNISCO14804100 SERIAL:711448290 014，220VACpressure controller
DYNISCOART.- NR. 1480-4-1-0-0pressure controller
DYNISCOPT4624
DYNISCOPT4634-5M-12-SIL2
DYNISCOMDA422-1/2-3.5C-23/46-GC8pressure sensor
DYNISCOPT4624
DYNISCOPT4624-35MPA-6/16-SIL2pressure sensor
DYNISCOTPT4634-1/2-5M-12/18-SIL2
DYNISCO14802101 SERIAL:657282010 007，24VDCpressure controller
DYNISCOART.- NR. 1480-2-1-0-1pressure controller
DYNISCOPT4624-5M-25/18pressure sensor
DYNISCOPT4624-15M-12-SIL2
DYNISCOART.- NR. 1480-4-1-0-0
DYNISCOPT4624-35MPA-6/16-SIL2
DYNISCOPT4624-1/2-15M-12/18-SIL2
DYNISCOPT462E-5M-6/18
DYNISCOPT4626-1/2-3M-18/18sensor
DYNISCOTYP PT462E ART. -NR. : PT462E-5M-6/18
DYNISCOART.- NR. 1480-1-0-0-0
DYNISCOART.- NR. SPX 4622-N-A-05-B-21-DP-DD-A-AF-ZZ-GC9
DYNISCOTPT463F-1/2-5M-12/18-S137-SIL2pressure sensor
DYNISCOSPX2242-S-A-00-M-22-CE-FF-BCA-ZZ-B171 Check the model, which is 500BAR. After that, it says 20MPA=200BAR. What exactly do you need
DYNISCOMDT422F-1/2-1C-15/46-B171-GC0pressure sensor
DYNISCOMDT422F-1/2-3.5C-15/46-B171-GC8pressure sensor
DYNISCOART. - NR. TPT4634-1/2-50MPA-6/18-SIL2 This quantity is validsensor
DYNISCOPT462E-35MPA-6/18
DYNISCOART.- NR. SPX 4222-N-A-00-B-21-CE-DD-A-AF-ZZ-GC9
DYNISCOPT4626-1/2-5M-6/18
DYNISCOTPT4634-1/2-3M-12/18-SIL2
DYNISCO1480pressure gauge
DYNISCOPT4624-1/2-5M-6/18-SIL2pressure sensor
DYNISCOPT4626-1/2-5M-6/18
DYNISCO2242NAOOM21HTAABCAZZB628
DYNISCOPT4626-1/2-5M-12/18pressure sensor
DYNISCOReplace 1490
DYNISCOSPX 2291EA 56M 13DPDDACAZZPressure transmitter
DYNISCOMDA462-1/2-3,5C-15/46pressure sensor
DYNISCOMDT460F-M18-1M-15-SIL2Fusion pressure sensor
DYNISCO200100
DYNISCO14804100pressure gauge
DYNISCO1480-4-1-0-0pressure gauge
DYNISCO14804101display table
DYNISCOMDT422F-1/2-2C-15/46-B171-GC0pressure sensor
DYNISCOMDT460F-M18-1M-15-SIL2Fusion pressure sensor
DYNISCO200925
DYNISCO1480-4-1-0-1display table
DYNISCOMDT462L-M18-7C-15/46
DYNISCODYMT-S-1/2-J-5-10-G-2M-F13
DYNISCOECHO-MV3-MPA-R21-UNF-6PN-S06-F18-NTR
DYNISCODYMT-S-1/2-2XJ-5-10-G
DYNISCO1480-4-1-0-1 discounted price for contracts already madedisplay table
DYNISCOPT462E-1/2-5M-6/18sensor
DYNISCOMDA462-1/2-3,5C-15/46pressure sensor
DYNISCOTPT4634-35MPA-12/18-S147-SIL2sensor
DYNISCOPT462E-3.5CB-6/18-GC8
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2 replacementsensor
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTRsensor
DYNISCO1480-4-1-0-1display table
DYNISCODYMT-F-1/2-PT100/3-0-15-G-Htemperature sensor
DYNISCOPT4624-1/2-20MPA-6/18-SIL2
DYNISCOMDT422F-1/2-2C-15/46-SIL2 replacementsensor
DYNISCO1480-4-1-0-0 is valid for the entire orderpressure gauge
DYNISCOPT390-0-15M-A191
DYNISCOMDT462FH-1/2-2C-15/46-SIL2 replacementpressure sensor
DYNISCOPT4626-M18-7CB-6/18
DYNISCOECHO-MV3-BAR-R20-UNF-6PN-S06-F18-NTR 200BAR
DYNISCODYMT-S-1/2-2XJ-5-10-G-F13
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2
DYNISCOVT460-10sensor wire
DYNISCOPT4626-M18-7CB-6/18
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR 350BAR
DYNISCODYMT-S-1/2-PT100/4-15-15-G
DYNISCOMDT420F-1/2-5C-32-SIL2pressure sensor
DYNISCOECHO-VT1-BAR-R21-UNF-6PN-S06-F18-NTR 替代
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR replacement
DYNISCOSPX 2242 at 00 m 21 ceffbcazzb 106
DYNISCOTPT4636-1/2-35MPA-6/18
DYNISCOTPT4636-1/2-10M-9/18-SIL2
DYNISCOPT462E-1/2-5M-6/18
DYNISCO4012228cable
DYNISCOMDT462F-1/2-1C-15/46-SIL2
DYNISCOIDA353-5C-10V-D21
DYNISCO1480-4-1-0-0 substitution
DYNISCOM14-70MPA-6/18
DYNISCOMDT462F-1/2-3,5C-15/46-GC8pressure sensor
DYNISCO14834100
DYNISCOMDT462F-1/2-3,5C-15/46-SIL2
DYNISCO14834100
DYNISCO14804100
DYNISCODYMT-F-1/2-PT100/3-0-15-G-H
DYNISCO14804100
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR replacementpressure sensor
DYNISCO2281-N-G-G-AC-5-P-19-A
DYNISCO4622-N-A-05-B-21-FE-DD-A-AF-ZZ-GC8
DYNISCOATC99040011
DYNISCOMDT462F-M18-7C-15/46-SIL2 replacement
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR
DYNISCO4622-N-A-05-B-21-FE-DD-A-AF-ZZ-GC8
DYNISCOMDT462F-1/2-7C-15/46
DYNISCOSPX2243-E-A-25-K-22-FE-FF-A-CA-ZZ-B171
DYNISCOMDT462L-M18-7C-15/46
DYNISCOIDA353-5C-10V-D21
DYNISCO1480-4-1-0-1
DYNISCO1480-4-1-0-0
DYNISCOECHO-MV3-BAR-R21-UNF-6PN-S06-F18-NTR
DYNISCOTPT4634-5M-15/18-SIL2
DYNISCOIDA353-7C-10V
DYNISCO14901
DYNISCO1480-4-1-0-1
DYNISCO1480-4-1-0-0pressure gauge
DYNISCO149041000
DYNISCOD7100 IDA353-3.5C
DYNISCO9966-7914
DYNISCOMDT462F-1/2-5C-23/46-B171-SIL2pressure sensor
DYNISCO1480-4-1-0-0
DYNISCODYKE-1/2-PT100/4-15-32-G-F14
DYNISCO1A422-1/2-3.5C-23/46-GC8/000ST
DYNISCOMDT462F-1/2-5C-15/46-B171-SIL2pressure sensor
ROEMHELD1891201
ROEMHELD1942000
ROEMHELD1895609
ROEMHELD0460831
ROEMHELD1283005
ROEMHELD1296120250
ROEMHELD1544165+0131156
ROEMHELD1545160L
ROEMHELD1895141M
ROEMHELD1896303VDH36
ROEMHELD2951417
ROEMHELD1895509
ROEMHELD9384006
ROEMHELD811968012
ROMHELD0132703
ROEMHELD0460656
ROEMHELD04601020
ROEMHELD1829743D00
ROEMHELD1850102M
ROEMHELD1895624M
ROEMHELD1829740D00
ROEMHELD1845L090L30M
ROMHELD9281136
ROEMHELD9281136
ROMHELD811968011
ROMHELD9384755
ROEMHELD0132732
ROMHELD9281-136
ROEMHELD3412044
ROMHELD9384735
ROEMHELD1895323
ROEMHELD1895503
ROEMHELD1942925
ROEMHELD4412974
ROEMHELD1942410P
ROEMHELD1547176
ROEMHELD1547210
ROEMHELD8755020
HELDHAIN555541-01
ROEMHELD1543105S
ROEMHELD1463101
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD1891121
ROEMHELD1801200
ROEMHELD1802200
ROEMHELD1463610
ROEMHELD1895604
ROEMHELD1895504
ROEMHELD1895604
FROEMHELD1942112
ROEMHELD804474
ROEMHELD704201
ROEMHELD1942201
ROMHELD1541105S
ROMHELD1545105S
ROEMHELD1875303
ROEMHELD1875403
ROMHELD1550196
ROMHELD3614070
ROMHELD1543523
ROMHELD1738-858
ROEMHELD9284036
ROEMHELD1896303VMH36
ROEMHELD4312151
ROEMHELD3829-234
ROEMHELD1547-513 is valid for the entire order
ROEMHELD1547-516
ROEMHELD3829-234
ROEMHELD3829-099
ROEMHELD3829234
ROEMHELD1547516
ROEMHELD0132478 1844-A0XXX24(M)
ROEMHELD0132689
ROEMHELD1942002
ROEMHELD1875303
ROEMHELD1875403
ROEMHELD1545105
ROEMHELD1543407
ROEMHELDPOINTS FOR 1843847
ROEMHELD3821246
ROEMHELD1543265
ROEMHELD1804230
ROEMHELD1942007
ROEMHELD1344165
ROEMHELD4317200
ROEMHELD8459001
ROEMHELD8145160
ROEMHELD1955932
ROEMHELD1472001
ROEMHELD1543101
ROMHELD8.2135.2820
ROEMHELD1471011M
ROEMHELDAlternative: 1824828A
ROEMHELD500071-
ROEMHELD500071
ROEMHELD1893504
ROEMHELD1893604
ROEMHELD1513020
ROEMHELD1955012
ROEMHELD120034
ROEMHELD70580
ROEMHELD199948
ROEMHELD196207
ROEMHELD1846A090R36
ROEMHELD1121987-00
ROEMHELD1846A090R36
ROEMHELD1846A090L36
ROEMHELD9208181
ROEMHELDARTICLE NO. 0460682
ROEMHELDS03642
ROEMHELDS03928
ROEMHELDS04156
ROEMHELDEEPDRDS3-05-115-5-24V
ROEMHELD1534136B
ROEMHELD3829228
ROEMHELD1533166
ROEMHELD3829228
ROEMHELD1534136B
ROEMHELD1533166
ROEMHELD1548105BH10
ROEMHELD1535196B
ROEMHELD1547106B
ROEMHELD1534166B
ROEMHELD1544165B
ROEMHELD1533166
ROEMHELD3829228 M12X1 MM
ROEMHELD1544105
ROEMHELD1544105B
ROEMHELD1533166
ROEMHELD1533166
ROEMHELD3829-228-M12
ROEMHELD3829228
ROEMHELD1533166
ROEMHELD1533166
ROEMHELD1534136B
ROEMHELD3829228
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD0460832
ROEMHELD0460836
ROEMHELD1534136B
ROEMHELD1533166
ROEMHELD0460836
ROEMHELD3829228
ROMHELD1897-275
ROEMHELD1533166
ROEMHELD29453
ROMHELD1464610
ROMHELD1543513
ROMHELD1544513
ROMHELD1544516
ROMHELD1895104
ROEMHELD1461110
ROEMHELD1803230
ROEMHELD1547110
ROEMHELD0460831
ROEMHELD18931191VI
ROEMHELD1895103
ROEMHELD15431144 is valid for the entire order
ROEMHELD15431140
ROEMHELD1803131B
ROEMHELD1579856
ROEMHELD804-474
ROEMHELD804 474
ROEMHELD0460730
ROEMHELD300199
ROEMHELD3001999
ROEMHELD1845N075L43M
ROEHMHELD1543265
ROEMHELD1893303
ROEMHELD1845F090L30
ROEMHELD1844F090R24
ROEMHELD1942010
ROEMHELD18911024
ROEMHELD1545210
ROEMHELD1296100450
ROEMHELD1297100500
ROEMHELD3829234
ROEMHELD3829099
ROEMHELD3829-234
ROEMHELD1546195 is valid for the entire order
ROEMHELD1547516B
ROEMHELD1824510A
ROEMHELD1461110
ROEMHELD1804230
ROEMHELD2954-429
ROEMHELD1804-121
ROEMHELD189-101M
ROEMHELD0460937
ROEMHELD2951416
ROEMHELDDiscontinued production to replace 2954620. The external dimensions are slightly smaller, but the connection dimensions are the same.
ROEMHELD102913-03
ROEMHELD146
ROEMHELD1942012
ROEMHELD1458002
ROEMHELD0132566
ROEMHELD1953858
ROEMHELD1941820
ROEMHELD1942-017
ROEMHELD1942010
ROEMHELD1942012
ROEMHELD1942017
ROEMHELD1953858
ROEMHELD1942010
ROEMHELD1458005
ROEMHELD1942017
ROEMHELD1458002
ROEMHELD1942117
ROEMHELD1942017
ROEMHELD3709012
ROEMHELD1942112
ROEMHELD1941-820
ROEMHELD1942010
ROEMHELD3707021
ROEMHELD3710081
ROEMHELD0132466 +1953858
ROEMHELD1546-210
ROEMHELD1458-002
ROEMHELD3610246
ROEMHELD9210-145
ROEMHELD1897208VMH38
ROEMHELD132125
ROEMHELD1942112
ROEMHELD5700013
ROEMHELD18951330M90
ROEMHELD1895133
ROEMHELD1824809A
ROEMHELD1546429L
ROEMHELD1551885
ROEMHELD1550939
ROEMHELD0132071 DICHTSATZ FKM FOR 1550-1X1
ROEMHELD1545105H10
ROEMHELD1471011
ROEMHELD1935802
ROEMHELD1933808
ROEMHELD1290288
ROEMHELD1290285
ROEMHELD1297130120
ROMHELD2954-429
ROMHELD1458-002
ROMHELDRPF 12-5
ROMHELD1942-000
ROEMHELD1942000
ROEMHELD1458002
ROEMHELD2954429
ROEMHELDRPF 12-5
ROEMHELD1885-104
ROEMHELD1545165
ROEMHELD1804-110
ROEMHELD1804-110
ROEMHELD1804130
ROEMHELD1534166
ROEMHELD575
ROEMHELD575
ROEMHELD4605932
ROEMHELD1953022
ROEMHELD1942925
ROEMHELD4412974
ROEMHELD1458001
ROEMHELD1942410P
ROMHELD1953022
ROMHELD1942925
ROMHELD4412974
ROMHELD0132384
ROEMHELD1854Q090R21M
ROEMHELD8804006
ROEMHELD3614075
ROEMHELDBS4253RB075N1
ROEMHELD9425-102
The cabbage fields on both sides of Lao Zhang's north and south are divided into three parts each. Lao Zhang hopes to obtain a small portion of water flow from the main waterway through a one-time waterway modification, with the water flow velocity as similar as possible to other fields, as shown in Figure 1. In this way, Lao Zhang can rest under the shade of trees for a while without making any changes to the waterway, and all the land can be watered at the same time.
A coupler is a radio frequency device that extracts a small portion of the signal from the wireless signal backbone channel, as shown in Figure 2. Like a power divider, it is a power distribution device, but the coupler is an unequal power distribution device. The combination of couplers and power dividers is mainly used to achieve a goal - to evenly distribute the transmission power of the signal source to each antenna port of the indoor distribution system, so that the transmission power of each antenna port is basically the same.
The input port power of an ideal coupler is equal to the sum of the coupling port power and the output port power, measured in watts (W)
As shown in Figure 3.
The important indicators of a coupler are coupling degree and insertion loss. The coupling degree is the ratio of the power between the coupling port and the input port, which is generally negative in dB. The larger the absolute value of the coupling degree, the less things are taken away, and the lower the loss of the natural coupler. Insertion loss is the ratio of power between the output port and the input port. The larger the absolute value of coupling degree, the smaller the absolute value of insertion loss.
If expressed in dB, there is the following relationship:
So, the relationship between the insertion loss (dB) and coupling degree (dB) of the coupler can be expressed as:
example:
A coupler with a coupling degree of -10dB has an insertion loss of -0.5dB. Taking the absolute value and considering the dielectric loss, the insertion loss is generally larger and varies from manufacturer to manufacturer. Generally, the insertion loss can be around 0.7dB.
If the input port power is 15dBm, then the power of the coupling port of this coupler is 15dBm-10dB=5dBm, and the power of the output port is 15dBm-0.7dB=14.3dBm.
Many people may ask this question: why is energy not conserved when 5dBm+14.3dmm>15dBm? The reason is simple, quantities in dBm cannot be added together.
Applying an electrical signal to the input of the optocoupler causes the light source to emit light, and the intensity of the light depends on the magnitude of the excitation current. After this light is irradiated onto the packaged photodetector, a photocurrent is generated due to the photoelectric effect, which is led out from the output of the photodetector, thus achieving the conversion of electricity to light to electricity.
1. Working Characteristics (Taking Phototransistor as an Example)
The common mode rejection ratio inside the optocoupler is very high. Because the coupling capacitance between the light-emitting tube and the receiver is very small (within 2pF), the common mode input voltage has little effect on the output current through the inter electrode coupling capacitance, resulting in a high common mode rejection ratio.
2. Output characteristics
The output characteristics of a optocoupler refer to the relationship between the bias voltage VCE applied to the photosensitive tube and the output current IC at a certain emission current IF. When IF=0, the light-emitting diode does not emit light, and the collector output current of the photosensitive transistor at this time is called dark current, which is generally very small. When IF>0, under a certain IF effect, the corresponding IC is basically independent of VCE. The variation between IC and IF is linearly related, and the output characteristics of the optocoupler measured by a semiconductor transistor characteristic diagram instrument are similar to those of a conventional transistor.
3. Optocouplers can be used as linear couplers
Provide a bias current on the light-emitting diode, and then couple the signal voltage to the light-emitting diode through a resistor. This way, the phototransistor receives a light signal that increases or decreases in the bias current, and its output current will vary linearly with the input signal voltage. Optocouplers can also operate in a switch state to transmit pulse signals. When transmitting pulse signals, there is a certain delay time between the input signal and the output signal, and the input and output delay times of optocouplers with different structures vary greatly.
Optoelectronic testing
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1. Use a multimeter to determine the quality, as shown in Figure 3. Disconnect the input power supply and measure the resistance of pins 1 and 2 using the R × 1k gear. The forward resistance should be several hundred ohms, the reverse resistance should be several tens of thousands of ohms, and the resistance between pins 3 and 4 should be infinite. 1. Any group between pin 2 and pins 3 and 4 has an infinite resistance value. After the input terminal is powered on, the resistance of pins 3 and 4 is very small. Adjusting the resistance between pins 3 and 4 of RP indicates that the device is functioning properly. Note: The R × 10k gear cannot be used, otherwise it may cause breakdown of the transmission tube.
2. Simple testing circuit: When the power is turned on, the LED does not light up. Pressing SB will make the LED light up. Adjusting the RP and LED light intensity will change, indicating that the tested optocoupler is good.
application
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1. Composition of switch circuit
When the input signal ui is at a low level, transistor V1 is in an off state, and the current of the light-emitting diode in optocoupler B1 is approximately zero. The resistance between output terminals Q11 and Q12 is very high, which is equivalent to the switch being "disconnected"; When UI is at high level, v1 conducts and the light-emitting diode in B1 emits light. The resistance between Q11 and Q12 decreases, which is equivalent to the switch being "turned on". This circuit is in a high-level conducting state because Ui is at low level and the switch is not connected. Similarly, when there is no signal (Ui is at low level), the switch conducts, so it is in a low-level conducting state
2. Composition of Logic Circuits
The circuit is an AND gate logic circuit. The logical expression is P=A.B. In the figure, two phototransistors are connected in series. Only when the input logic levels A=1 and B=1, the output P=1. Similarly, logic circuits such as "OR gate", "NAND gate", and "OR NOT gate" can also be formed
3. Form an isolated coupling circuit
The circuit is shown in Figure 4. This is a typical AC coupled amplifier circuit. By appropriately selecting the current limiting resistor Rl of the light-emitting circuit, the current transfer ratio of B4 can be kept constant to ensure the linear amplification effect of the circuit.
4. Form a high-voltage voltage regulator circuit
The driving transistor needs to use a transistor with high voltage resistance (the driving transistor in the figure is 3DG27). When the output voltage increases, the bias voltage of V55 increases, and the forward current of the light-emitting diode in B5 increases, causing the inter electrode voltage of the photosensitive tube to decrease. The bias voltage of the junction of the tube is adjusted to decrease while the internal resistance increases, resulting in a decrease in the output voltage while maintaining its stability
5. Assemble the automatic control circuit for the lobby lighting
A is four sets of analog electronic switches (S1~S4): S1, S2, S3 are connected in parallel (to increase driving power and anti-interference ability) for the delay circuit. When it is powered on, R4 and B6 drive the bidirectional thyristor VT, which directly controls the hall lighting H; S4 and external photoresistor Rl form an environmental light detection circuit. When the door is closed, the normally closed reed switch KD installed on the door frame is subjected to the action of the magnet on the door, and its contacts are disconnected, with S1, S2, and S3 in the data open state. At night, when the host returns home and opens the door, the magnet moves away from KD and the KD contact closes. At this time, the 9V power supply is rectified and charged to C1 through R1. The voltage at both ends of C1 quickly rises to 9V. The rectified voltage, through S1, S2, S3, and R4, causes the light-emitting tube in B6 to emit light, triggering the bidirectional thyristor to conduct. VT also conducts, and H lights up, achieving automatic lighting control. After the door is closed, the magnet controls KD, the contacts are disconnected, the 9V power supply stops charging C1, and the circuit enters a delay state. C1 begins to discharge R3, and after a delay, the voltage at both ends of C1 gradually drops below the turn-on voltage (1.5v) of S1, S2, and S3. S1, S2, and S3 return to the disconnected state, causing B6 to turn off, VT to turn off, and H to turn off, achieving the delayed light off function.
Distinguish types
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Directional type
A directional coupler is a four port component with directional transmission characteristics, consisting of two pairs of transmission systems connected by coupling devices. Firstly, introduce the performance indicators of directional couplers, followed by waveguide dual hole directional couplers, dual branch directional couplers, and parallel coupled microstrip directional couplers.
1) Performance indicators of directional couplers
A directional coupler is a four port network, with port "①" as the input terminal, port "②" as the direct output terminal, port "③" as the coupled output terminal, and port "④" as the isolation terminal. Its scattering matrix is set to [S]. The performance indicators of a directional coupler include coupling degree, isolation degree, orientation degree, input standing wave ratio, and operating bandwidth. Please introduce them separately below.
2) Isolation degree
The ratio of the input power P1 of input terminal "①" to the output power P4 of isolation terminal "④" is defined as the isolation degree, denoted as I.
⑶ Orientation degree
The ratio of the output power P3 of the coupling end "③" to the output power P4 of the isolation end "④" is defined as directionality, denoted as D.
⑷ Input standing wave ratio
The standing wave ratio of input port ① when ports ②, ③, and ④ are all connected to matching loads is defined as the input standing wave ratio, denoted as ρ.
⑸ Working bandwidth
The working bandwidth refers to the frequency range within which the parameters C, I, D, and ρ of the directional coupler meet the requirements.
Types of waveguides
The waveguide dual hole directional coupler is a waveguide directional coupler, in which the main and auxiliary waveguides pass through two common narrow walls
A small hole with a distance of d=(2n+1) λ g0/4 is used to achieve coupling, where λ g0 is the waveguide wavelength corresponding to the center frequency and n is a positive integer, generally taken as n=0. The coupling hole is generally circular, but can also be of other shapes. When working at the center frequency, β d=π/2, at which point D →∞; When deviating from the center frequency, sec β d has a certain value, at which point D is no longer infinite. In fact, even at the center frequency, the directionality of the dual hole coupler is not infinite, but can only be around 30dB.
In short, the waveguide dual hole directional coupler relies on the mutual interference of waves to achieve directional output of the main waveguide, with in-phase superposition at the coupling port and inverse cancellation at the isolation port. In order to increase the coupling degree of the directional coupler and broaden the operating frequency band, a porous directional coupler can be used,
Double classification types
The dual branch directional coupler consists of a main line, a secondary line, and two branch lines, where the branch line
The length and spacing are both 1/4 of the center wavelength, as shown in Figure 5-15. The characteristic impedance of the main entrance line "①" is, the characteristic impedance of the main exit line "②" is (k is the impedance transformation ratio), the characteristic impedance of the isolation end "④" of the secondary line is, the characteristic impedance of the coupling end "③" of the secondary line is, the characteristic impedance of the parallel connection line is Z0p, and the characteristic impedances of the two branch lines are and, respectively.
Parallel types
Parallel coupled microstrip directional coupler is a type of reverse directional coupler, with its coupled output end on the same side as the main input end, as shown in the figure on the right. Port in is the input port, port out is the through port, port Ocap is the coupling port, and port "④" is the isolation port.
Technical specifications for couplers (indoor distribution)
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Table 2 Technical specifications of couplers
project
specification
5dB
7dB
10dB
15dB
20dB
insertion loss
≤1.7dB
≤1.2dB
≤0.7dB
≤0.3dB
≤0.3dB
VSW standing wave ratio
≤1.4
Coupling loss
5dB
7dB
10dB
15dB
20dB
Maximum input power
15W
Type of connector (interface)
N-Female
isolator
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Isolators, also known as inverters, experience almost no attenuation when electromagnetic waves pass through them in the forward direction, but significant attenuation when they pass through them in the reverse direction. Common isolators include harmonic isolators
There are two types: vibration type and field displacement type.
Resonant isolator
Due to the anisotropy of ferrite, under a constant magnetic field Hi, the left and right circularly polarized rotating magnetic fields that form a left and right spiral relationship with the Hi direction have different permeabilities (denoted as μ - and μ+, respectively). At a certain point on a microwave transmission line containing ferrite materials, a left-handed magnetic field is transmitted along the+z direction, and a right-handed magnetic field is transmitted along the - z direction. The two transmit the same distance, but the corresponding magnetic permeability is different. Therefore, the phase velocities of the left-handed and right-handed magnetic fields are different, resulting in different phase shifts. This is the irreversibility of ferrite phase shifts. On the other hand, ferrite exhibits ferromagnetic resonance effect and resonant absorption effect of circularly polarized magnetic field.
The so-called ferromagnetic resonance effect of ferrite refers to the maximum absorption of microwave energy by ferrite when the operating frequency ω of the magnetic field is equal to the resonant angular frequency ω 0 of ferrite. For circularly polarized magnetic fields, left and right polarized magnetic fields have different magnetic permeabilities, resulting in different absorption characteristics for both.
For a right-handed polarized magnetic field with a magnetic permeability of μ+in reverse transmission, it exhibits ferromagnetic resonance effect, while for a left-handed polarized magnetic field with a magnetic permeability of μ - in forward transmission, it does not exhibit ferromagnetic resonance characteristics, which is the resonance effect of a circularly polarized magnetic field. The ferrite resonant isolator is made by utilizing this characteristic of ferrite.
Field moving isolator
Field shift isolators are made based on the different field shift effects of ferrite on the wave modes transmitted in two directions.
It adds attenuation plates on the side of the ferrite sheet, and due to the different deviations of the fields generated by the two directions of transmission, the electric field of the wave transmitted in the forward direction (- z direction) is biased towards the side without attenuation plates, while the electric field of the wave transmitted in the reverse direction (+z direction) is biased towards the side of attenuation plates, thus achieving the isolation function of small forward attenuation and large reverse attenuation, as shown in Figure 5-32.
Due to its small size, light weight, simple structure, and wide operating frequency band, field moving isolators have been widely used in low-power applications
The cabbage fields on both sides of Lao Zhang's north and south are divided into three parts each. Lao Zhang hopes to obtain a small portion of water flow from the main waterway through a one-time waterway modification, with the water flow velocity as similar as possible to other fields, as shown in Figure 1. In this way, Lao Zhang can rest under the shade of trees for a while without making any changes to the waterway, and all the land can be watered at the same time.
A coupler is a radio frequency device that extracts a small portion of the signal from the wireless signal backbone channel, as shown in Figure 2. Like a power divider, it is a power distribution device, but the coupler is an unequal power distribution device. The combination of couplers and power dividers is mainly used to achieve a goal - to evenly distribute the transmission power of the signal source to each antenna port of the indoor distribution system, so that the transmission power of each antenna port is basically the same.
The input port power of an ideal coupler is equal to the sum of the coupling port power and the output port power, measured in watts (W)
As shown in Figure 3.
The important indicators of a coupler are coupling degree and insertion loss. The coupling degree is the ratio of the power between the coupling port and the input port, which is generally negative in dB. The larger the absolute value of the coupling degree, the less things are taken away, and the lower the loss of the natural coupler. Insertion loss is the ratio of power between the output port and the input port. The larger the absolute value of coupling degree, the smaller the absolute value of insertion loss.
If expressed in dB, there is the following relationship:
So, the relationship between the insertion loss (dB) and coupling degree (dB) of the coupler can be expressed as:
example:
A coupler with a coupling degree of -10dB has an insertion loss of -0.5dB. Taking the absolute value and considering the dielectric loss, the insertion loss is generally larger and varies from manufacturer to manufacturer. Generally, the insertion loss can be around 0.7dB.
If the input port power is 15dBm, then the power of the coupling port of this coupler is 15dBm-10dB=5dBm, and the power of the output port is 15dBm-0.7dB=14.3dBm.
Many people may ask this question: why is energy not conserved when 5dBm+14.3dmm>15dBm? The reason is simple, quantities in dBm cannot be added together.
Applying an electrical signal to the input of the optocoupler causes the light source to emit light, and the intensity of the light depends on the magnitude of the excitation current. After this light is irradiated onto the packaged photodetector, a photocurrent is generated due to the photoelectric effect, which is led out from the output of the photodetector, thus achieving the conversion of electricity to light to electricity.
1. Working Characteristics (Taking Phototransistor as an Example)
The common mode rejection ratio inside the optocoupler is very high. Because the coupling capacitance between the light-emitting tube and the receiver is very small (within 2pF), the common mode input voltage has little effect on the output current through the inter electrode coupling capacitance, resulting in a high common mode rejection ratio.
2. Output characteristics
The output characteristics of a optocoupler refer to the relationship between the bias voltage VCE applied to the photosensitive tube and the output current IC at a certain emission current IF. When IF=0, the light-emitting diode does not emit light, and the collector output current of the photosensitive transistor at this time is called dark current, which is generally very small. When IF>0, under a certain IF effect, the corresponding IC is basically independent of VCE. The variation between IC and IF is linearly related, and the output characteristics of the optocoupler measured by a semiconductor transistor characteristic diagram instrument are similar to those of a conventional transistor.
3. Optocouplers can be used as linear couplers
Provide a bias current on the light-emitting diode, and then couple the signal voltage to the light-emitting diode through a resistor. This way, the phototransistor receives a light signal that increases or decreases in the bias current, and its output current will vary linearly with the input signal voltage. Optocouplers can also operate in a switch state to transmit pulse signals. When transmitting pulse signals, there is a certain delay time between the input signal and the output signal, and the input and output delay times of optocouplers with different structures vary greatly.
Optoelectronic testing
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1. Use a multimeter to determine the quality, as shown in Figure 3. Disconnect the input power supply and measure the resistance of pins 1 and 2 using the R × 1k gear. The forward resistance should be several hundred ohms, the reverse resistance should be several tens of thousands of ohms, and the resistance between pins 3 and 4 should be infinite. 1. Any group between pin 2 and pins 3 and 4 has an infinite resistance value. After the input terminal is powered on, the resistance of pins 3 and 4 is very small. Adjusting the resistance between pins 3 and 4 of RP indicates that the device is functioning properly. Note: The R × 10k gear cannot be used, otherwise it may cause breakdown of the transmission tube.
2. Simple testing circuit: When the power is turned on, the LED does not light up. Pressing SB will make the LED light up. Adjusting the RP and LED light intensity will change, indicating that the tested optocoupler is good.
application
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1. Composition of switch circuit
When the input signal ui is at a low level, transistor V1 is in an off state, and the current of the light-emitting diode in optocoupler B1 is approximately zero. The resistance between output terminals Q11 and Q12 is very high, which is equivalent to the switch being "disconnected"; When UI is at high level, v1 conducts and the light-emitting diode in B1 emits light. The resistance between Q11 and Q12 decreases, which is equivalent to the switch being "turned on". This circuit is in a high-level conducting state because Ui is at low level and the switch is not connected. Similarly, when there is no signal (Ui is at low level), the switch conducts, so it is in a low-level conducting state
2. Composition of Logic Circuits
The circuit is an AND gate logic circuit. The logical expression is P=A.B. In the figure, two phototransistors are connected in series. Only when the input logic levels A=1 and B=1, the output P=1. Similarly, logic circuits such as "OR gate", "NAND gate", and "OR NOT gate" can also be formed
3. Form an isolated coupling circuit
The circuit is shown in Figure 4. This is a typical AC coupled amplifier circuit. By appropriately selecting the current limiting resistor Rl of the light-emitting circuit, the current transfer ratio of B4 can be kept constant to ensure the linear amplification effect of the circuit.
4. Form a high-voltage voltage regulator circuit
The driving transistor needs to use a transistor with high voltage resistance (the driving transistor in the figure is 3DG27). When the output voltage increases, the bias voltage of V55 increases, and the forward current of the light-emitting diode in B5 increases, causing the inter electrode voltage of the photosensitive tube to decrease. The bias voltage of the junction of the tube is adjusted to decrease while the internal resistance increases, resulting in a decrease in the output voltage while maintaining its stability
5. Assemble the automatic control circuit for the lobby lighting
A is four sets of analog electronic switches (S1~S4): S1, S2, S3 are connected in parallel (to increase driving power and anti-interference ability) for the delay circuit. When it is powered on, R4 and B6 drive the bidirectional thyristor VT, which directly controls the hall lighting H; S4 and external photoresistor Rl form an environmental light detection circuit. When the door is closed, the normally closed reed switch KD installed on the door frame is subjected to the action of the magnet on the door, and its contacts are disconnected, with S1, S2, and S3 in the data open state. At night, when the host returns home and opens the door, the magnet moves away from KD and the KD contact closes. At this time, the 9V power supply is rectified and charged to C1 through R1. The voltage at both ends of C1 quickly rises to 9V. The rectified voltage, through S1, S2, S3, and R4, causes the light-emitting tube in B6 to emit light, triggering the bidirectional thyristor to conduct. VT also conducts, and H lights up, achieving automatic lighting control. After the door is closed, the magnet controls KD, the contacts are disconnected, the 9V power supply stops charging C1, and the circuit enters a delay state. C1 begins to discharge R3, and after a delay, the voltage at both ends of C1 gradually drops below the turn-on voltage (1.5v) of S1, S2, and S3. S1, S2, and S3 return to the disconnected state, causing B6 to turn off, VT to turn off, and H to turn off, achieving the delayed light off function.
Distinguish types
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Directional type
A directional coupler is a four port component with directional transmission characteristics, consisting of two pairs of transmission systems connected by coupling devices. Firstly, introduce the performance indicators of directional couplers, followed by waveguide dual hole directional couplers, dual branch directional couplers, and parallel coupled microstrip directional couplers.
1) Performance indicators of directional couplers
A directional coupler is a four port network, with port "①" as the input terminal, port "②" as the direct output terminal, port "③" as the coupled output terminal, and port "④" as the isolation terminal. Its scattering matrix is set to [S]. The performance indicators of a directional coupler include coupling degree, isolation degree, orientation degree, input standing wave ratio, and operating bandwidth. Please introduce them separately below.
2) Isolation degree
The ratio of the input power P1 of input terminal "①" to the output power P4 of isolation terminal "④" is defined as the isolation degree, denoted as I.
⑶ Orientation degree
The ratio of the output power P3 of the coupling end "③" to the output power P4 of the isolation end "④" is defined as directionality, denoted as D.
⑷ Input standing wave ratio
The standing wave ratio of input port ① when ports ②, ③, and ④ are all connected to matching loads is defined as the input standing wave ratio, denoted as ρ.
⑸ Working bandwidth
The working bandwidth refers to the frequency range within which the parameters C, I, D, and ρ of the directional coupler meet the requirements.
Types of waveguides
The waveguide dual hole directional coupler is a waveguide directional coupler, in which the main and auxiliary waveguides pass through two common narrow walls
A small hole with a distance of d=(2n+1) λ g0/4 is used to achieve coupling, where λ g0 is the waveguide wavelength corresponding to the center frequency and n is a positive integer, generally taken as n=0. The coupling hole is generally circular, but can also be of other shapes. When working at the center frequency, β d=π/2, at which point D →∞; When deviating from the center frequency, sec β d has a certain value, at which point D is no longer infinite. In fact, even at the center frequency, the directionality of the dual hole coupler is not infinite, but can only be around 30dB.
In short, the waveguide dual hole directional coupler relies on the mutual interference of waves to achieve directional output of the main waveguide, with in-phase superposition at the coupling port and inverse cancellation at the isolation port. In order to increase the coupling degree of the directional coupler and broaden the operating frequency band, a porous directional coupler can be used,
Double classification types
The dual branch directional coupler consists of a main line, a secondary line, and two branch lines, where the branch line
The length and spacing are both 1/4 of the center wavelength, as shown in Figure 5-15. The characteristic impedance of the main entrance line "①" is, the characteristic impedance of the main exit line "②" is (k is the impedance transformation ratio), the characteristic impedance of the isolation end "④" of the secondary line is, the characteristic impedance of the coupling end "③" of the secondary line is, the characteristic impedance of the parallel connection line is Z0p, and the characteristic impedances of the two branch lines are and, respectively.
Parallel types
Parallel coupled microstrip directional coupler is a type of reverse directional coupler, with its coupled output end on the same side as the main input end, as shown in the figure on the right. Port in is the input port, port out is the through port, port Ocap is the coupling port, and port "④" is the isolation port.
Technical specifications for couplers (indoor distribution)
broadcast
edit
Table 2 Technical specifications of couplers
project
specification
5dB
7dB
10dB
15dB
20dB
insertion loss
≤1.7dB
≤1.2dB
≤0.7dB
≤0.3dB
≤0.3dB
VSW standing wave ratio
≤1.4
Coupling loss
5dB
7dB
10dB
15dB
20dB
Maximum input power
15W
Type of connector (interface)
N-Female
isolator
broadcast
edit
Isolators, also known as inverters, experience almost no attenuation when electromagnetic waves pass through them in the forward direction, but significant attenuation when they pass through them in the reverse direction. Common isolators include harmonic isolators
There are two types: vibration type and field displacement type.
Resonant isolator
Due to the anisotropy of ferrite, under a constant magnetic field Hi, the left and right circularly polarized rotating magnetic fields that form a left and right spiral relationship with the Hi direction have different permeabilities (denoted as μ - and μ+, respectively). At a certain point on a microwave transmission line containing ferrite materials, a left-handed magnetic field is transmitted along the+z direction, and a right-handed magnetic field is transmitted along the - z direction. The two transmit the same distance, but the corresponding magnetic permeability is different. Therefore, the phase velocities of the left-handed and right-handed magnetic fields are different, resulting in different phase shifts. This is the irreversibility of ferrite phase shifts. On the other hand, ferrite exhibits ferromagnetic resonance effect and resonant absorption effect of circularly polarized magnetic field.
The so-called ferromagnetic resonance effect of ferrite refers to the maximum absorption of microwave energy by ferrite when the operating frequency ω of the magnetic field is equal to the resonant angular frequency ω 0 of ferrite. For circularly polarized magnetic fields, left and right polarized magnetic fields have different magnetic permeabilities, resulting in different absorption characteristics for both.
For a right-handed polarized magnetic field with a magnetic permeability of μ+in reverse transmission, it exhibits ferromagnetic resonance effect, while for a left-handed polarized magnetic field with a magnetic permeability of μ - in forward transmission, it does not exhibit ferromagnetic resonance characteristics, which is the resonance effect of a circularly polarized magnetic field. The ferrite resonant isolator is made by utilizing this characteristic of ferrite.
Field moving isolator
Field shift isolators are made based on the different field shift effects of ferrite on the wave modes transmitted in two directions.
It adds attenuation plates on the side of the ferrite sheet, and due to the different deviations of the fields generated by the two directions of transmission, the electric field of the wave transmitted in the forward direction (- z direction) is biased towards the side without attenuation plates, while the electric field of the wave transmitted in the reverse direction (+z direction) is biased towards the side of attenuation plates, thus achieving the isolation function of small forward attenuation and large reverse attenuation, as shown in Figure 5-32.
Due to its small size, light weight, simple structure, and wide operating frequency band, field moving isolators have been widely used in low-power applications