Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37218
T. Aoki
Reported improvements in resonances observed in a semianechoic radio frequency interference (RFI) measurement chamber are discussed. Due to the chamber's construction details and antenna placement, for 90 MHz measurements one point within the chamber had decreased electric-field intensity while another point showed the opposite. After lining the chamber's ceiling and for walls with about 13000 ferrite tiles, the points with unusually high or low field strengths were almost totally eliminated. This result confirmed that the chamber walls were responsible for reflections causing the measured field values and theoretical phase difference between the incident and reflected waves for the ferrite tiles is 90 degrees at 90 MHz accounting for the elimination of the reflections.<>
{"title":"The improvement of the resonance in RFI chamber","authors":"T. Aoki","doi":"10.1109/NSEMC.1989.37218","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37218","url":null,"abstract":"Reported improvements in resonances observed in a semianechoic radio frequency interference (RFI) measurement chamber are discussed. Due to the chamber's construction details and antenna placement, for 90 MHz measurements one point within the chamber had decreased electric-field intensity while another point showed the opposite. After lining the chamber's ceiling and for walls with about 13000 ferrite tiles, the points with unusually high or low field strengths were almost totally eliminated. This result confirmed that the chamber walls were responsible for reflections causing the measured field values and theoretical phase difference between the incident and reflected waves for the ferrite tiles is 90 degrees at 90 MHz accounting for the elimination of the reflections.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134498309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37202
L. Millanta, M. Forti
A classification and related terminology is suggested for the description of voltage disturbances on AC power lines. The current usage in the technical literature and in industrial and instrumentation applications has been incorporated. The disturbances are classed into two categories: waveshape disturbances and superimposed disturbances. The waveshape disturbances are further differentiated according to the type of voltage variations (over- or under-voltages) which are in turn subdivided according to a limit in time duration. The superimposed disturbances are subdivided into persistent and transient types. The former are present as a continuous voltage variation, for an extended period of time, and can be further subdivided into coherent having a definite frequency spectrum, or random, having a continuous frequency distribution. A persistent random disturbance can be described as stationary or nonstationary, according to whether its spectrum has a statistically constant or nonconstant power density. Experimental examples of transient disturbances are presented and discussed in the light of the proposed terminology and of the physical phenomena (characteristics, origin, propagation, coupling, natural oscillations) involved.<>
{"title":"A classification of the power-line voltage disturbances for an exhaustive description and measurement","authors":"L. Millanta, M. Forti","doi":"10.1109/NSEMC.1989.37202","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37202","url":null,"abstract":"A classification and related terminology is suggested for the description of voltage disturbances on AC power lines. The current usage in the technical literature and in industrial and instrumentation applications has been incorporated. The disturbances are classed into two categories: waveshape disturbances and superimposed disturbances. The waveshape disturbances are further differentiated according to the type of voltage variations (over- or under-voltages) which are in turn subdivided according to a limit in time duration. The superimposed disturbances are subdivided into persistent and transient types. The former are present as a continuous voltage variation, for an extended period of time, and can be further subdivided into coherent having a definite frequency spectrum, or random, having a continuous frequency distribution. A persistent random disturbance can be described as stationary or nonstationary, according to whether its spectrum has a statistically constant or nonconstant power density. Experimental examples of transient disturbances are presented and discussed in the light of the proposed terminology and of the physical phenomena (characteristics, origin, propagation, coupling, natural oscillations) involved.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129323972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37214
J. Lovetri, S. Abu-Hakima, A. Podgórski, G. Costache
The application of expert-system techniques to the electromagnetic hardening domain is briefly described with regard to a prototype named HardSys, written in Prolog and containing a subset of the domain knowledge. In this system the domain knowledge is partitioned into four electromagnetic hardening considerations: the ambient field; the shielding effectiveness; the system susceptibility; and the probability of failure. Each of these hardening requirements is implemented as a separate adviser module. Each module can be used independently and each can use information produced by any of the other modules if that information is available and/or required. Such is the case, for example, with the probability of failure module which requires the knowledge deduced from the ambient field, the shielding effectiveness, and the equipment susceptibility advisers. Preliminary results are reported to be encouraging.<>
{"title":"HardSys-applying expert system techniques to electromagnetic hardening","authors":"J. Lovetri, S. Abu-Hakima, A. Podgórski, G. Costache","doi":"10.1109/NSEMC.1989.37214","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37214","url":null,"abstract":"The application of expert-system techniques to the electromagnetic hardening domain is briefly described with regard to a prototype named HardSys, written in Prolog and containing a subset of the domain knowledge. In this system the domain knowledge is partitioned into four electromagnetic hardening considerations: the ambient field; the shielding effectiveness; the system susceptibility; and the probability of failure. Each of these hardening requirements is implemented as a separate adviser module. Each module can be used independently and each can use information produced by any of the other modules if that information is available and/or required. Such is the case, for example, with the probability of failure module which requires the knowledge deduced from the ambient field, the shielding effectiveness, and the equipment susceptibility advisers. Preliminary results are reported to be encouraging.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128539099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37189
Wang Zhaohua
The discrete Walsh transform is defined over a finite interval and produces undesirable blocking effects in digital image processing. It is shown how significant improvement can be obtained in eliminating the blocking problem by introducing the overlapping matrix Q and its false inverse Q for dyadic drift Walsh functions. This is applied to a two-dimensional overlapping sequency filter and an overlapping dyadic differentiation operator.<>
{"title":"Overlapping dyadic drift","authors":"Wang Zhaohua","doi":"10.1109/NSEMC.1989.37189","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37189","url":null,"abstract":"The discrete Walsh transform is defined over a finite interval and produces undesirable blocking effects in digital image processing. It is shown how significant improvement can be obtained in eliminating the blocking problem by introducing the overlapping matrix Q and its false inverse Q for dyadic drift Walsh functions. This is applied to a two-dimensional overlapping sequency filter and an overlapping dyadic differentiation operator.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117011891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37206
C. Brench, B. L. Brench
A number of antenna geometries are examined for radiation resistance and input reactance. More importantly, the effects of apparently small changes are evaluated to determine the frequency dependence of the equipment under test antennas. The models given are evaluated for frequencies up to 100 MHz; this the region where most cable-related effects are observed. The geometries considered are normalized to 1-m cables. Small changes are then made to the layout, followed by a reevaluation of the antenna effects. No attempt is made to provide information as to the directivity of these geometries. The models presented are based on single open-circuit (monopole) and closed circuit (loop) antennas. It is shown how some very-well-shielded and properly bonded cables must be included into the antenna model.<>
{"title":"Effects of cable and peripheral placement on radiated emissions","authors":"C. Brench, B. L. Brench","doi":"10.1109/NSEMC.1989.37206","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37206","url":null,"abstract":"A number of antenna geometries are examined for radiation resistance and input reactance. More importantly, the effects of apparently small changes are evaluated to determine the frequency dependence of the equipment under test antennas. The models given are evaluated for frequencies up to 100 MHz; this the region where most cable-related effects are observed. The geometries considered are normalized to 1-m cables. Small changes are then made to the layout, followed by a reevaluation of the antenna effects. No attempt is made to provide information as to the directivity of these geometries. The models presented are based on single open-circuit (monopole) and closed circuit (loop) antennas. It is shown how some very-well-shielded and properly bonded cables must be included into the antenna model.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115487234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37179
E. Joffe
The out-of-band response of an antenna is an important factor in determining the receiving system's susceptibility to the RF environment in which it is required to operate. A method for measuring the response of antennas below band is presented that is reliable, repeatable, and simulates to a high level of confidence plane wave conditions-the actual propagation mode that all airborne communication/navigation (COMM/NAV) antennas sense from most ground emitters and broadcast stations. The method has shown that the gain of most airborne COMM/NAV antennas is approximately -60 dBi, in the higher frequency range, to -120 dBi, in the lower frequency range, depending on the antenna. The VHF Whip antenna presents higher gain, due to its mechanical dimensions.<>
{"title":"Out-of-band response of VHF/UHF airborne antennae","authors":"E. Joffe","doi":"10.1109/NSEMC.1989.37179","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37179","url":null,"abstract":"The out-of-band response of an antenna is an important factor in determining the receiving system's susceptibility to the RF environment in which it is required to operate. A method for measuring the response of antennas below band is presented that is reliable, repeatable, and simulates to a high level of confidence plane wave conditions-the actual propagation mode that all airborne communication/navigation (COMM/NAV) antennas sense from most ground emitters and broadcast stations. The method has shown that the gain of most airborne COMM/NAV antennas is approximately -60 dBi, in the higher frequency range, to -120 dBi, in the lower frequency range, depending on the antenna. The VHF Whip antenna presents higher gain, due to its mechanical dimensions.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115764655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37191
K. Moy, W. Sperber
Current work on electromagnetic compatibility (EMC) requirements for automotive electronic and electrical components has necessitated the development of certain test procedures and specifications for EMC testing within General Motors. In order to support this effort, a study was performed to characterize the internal electromagnetic environment of the automobile. The authors describe the conducted susceptibility and conducted emissions test procedure and specification development in General Motors. The status of the development of similar test procedures in the Society of Automotive Engineers and International Standard Organization is also discussed. The test methods, where possible, harmonize with both national and international standards. Through these procedures correlation of component tests to the automobile's internal electromagnetic environment was established. Confirmation of site-to-site repeatability and device-to-device repeatability was accomplished. Test configurations were defined to ensure test uniformity and repeatability. Waveform severity levels were identified and recommended with the understanding that the final decision for severity-level specifications is the responsibility of the customer. The tests were primarily developed to be used during the design and development stages of components. In such cases, it is recommended that additional analytical methods such as frequency-domain analysis be used.<>
{"title":"Test procedure development for automotive conducted susceptibility and conducted emissions","authors":"K. Moy, W. Sperber","doi":"10.1109/NSEMC.1989.37191","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37191","url":null,"abstract":"Current work on electromagnetic compatibility (EMC) requirements for automotive electronic and electrical components has necessitated the development of certain test procedures and specifications for EMC testing within General Motors. In order to support this effort, a study was performed to characterize the internal electromagnetic environment of the automobile. The authors describe the conducted susceptibility and conducted emissions test procedure and specification development in General Motors. The status of the development of similar test procedures in the Society of Automotive Engineers and International Standard Organization is also discussed. The test methods, where possible, harmonize with both national and international standards. Through these procedures correlation of component tests to the automobile's internal electromagnetic environment was established. Confirmation of site-to-site repeatability and device-to-device repeatability was accomplished. Test configurations were defined to ensure test uniformity and repeatability. Waveform severity levels were identified and recommended with the understanding that the final decision for severity-level specifications is the responsibility of the customer. The tests were primarily developed to be used during the design and development stages of components. In such cases, it is recommended that additional analytical methods such as frequency-domain analysis be used.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"176 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114337747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37198
B. D. Berman
An integral expression for the low-frequency mutual inductance between a short linear track (exhibiting a rectangular conductor cross-section) and a noncoplanar, parallel, rectangular loop (exhibiting negligible conductor cross-section) is derived in terms of printed-circuit board (PCB) parameters. These parameters are: the wire-to-loop planar separation, the loop dimensions, the wire-to-loop lateral and longitudinal offsets, and the linear track cross-section. This expression yields numerical results which compare favorably to mutual inductance values calculated by other researchers using finite-element methods. Families of curves, computed from the integral expression, are presented as a PCB design tool.<>
{"title":"The mutual inductance of a linear current source and a non-coplanar, parallel, rectangular loop","authors":"B. D. Berman","doi":"10.1109/NSEMC.1989.37198","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37198","url":null,"abstract":"An integral expression for the low-frequency mutual inductance between a short linear track (exhibiting a rectangular conductor cross-section) and a noncoplanar, parallel, rectangular loop (exhibiting negligible conductor cross-section) is derived in terms of printed-circuit board (PCB) parameters. These parameters are: the wire-to-loop planar separation, the loop dimensions, the wire-to-loop lateral and longitudinal offsets, and the linear track cross-section. This expression yields numerical results which compare favorably to mutual inductance values calculated by other researchers using finite-element methods. Families of curves, computed from the integral expression, are presented as a PCB design tool.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125985877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37169
D. Golzio, S. Graffi, G. Masetti
A description is given of the design of two macromodels for the 741 operational amplifier to be used for computer code simulation of electromagnetic interference (EMI) effects. These macromodels are designed with the ability to work outside the nominal frequency bandwidth of the real circuit in order to simulate the consequences of small and large amplitude signals representing EMI effects. The design starts with the analysis (via numerical simulations) of the full device level model. After the macromodel has been defined, its behavior is adjusted by comparison to experimental measurements on different circuit configurations and interference sources. Measured and simulated results are in agreement.<>
{"title":"New circuit modeling of operational amplifiers","authors":"D. Golzio, S. Graffi, G. Masetti","doi":"10.1109/NSEMC.1989.37169","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37169","url":null,"abstract":"A description is given of the design of two macromodels for the 741 operational amplifier to be used for computer code simulation of electromagnetic interference (EMI) effects. These macromodels are designed with the ability to work outside the nominal frequency bandwidth of the real circuit in order to simulate the consequences of small and large amplitude signals representing EMI effects. The design starts with the analysis (via numerical simulations) of the full device level model. After the macromodel has been defined, its behavior is adjusted by comparison to experimental measurements on different circuit configurations and interference sources. Measured and simulated results are in agreement.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122776443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37172
D. R. Friesen, V. Flores
When performing various electromagnetic emissions tests, rotation of the equipment under test is often accomplished by the use of turntables. The increasing use of flush mounted metal turntables, instead of above-ground nonmetallic turntables, leads to the problem of how to characterize the interface between the metallic turntable and the ground plane. Several different approaches are used to address this problem: ignoring it, single-point grounding, capacitive coupling, and massively parallel grounding. Site attenuation measurements were made at an open-area test site that has a 12 m by 42 m ground screen and an 8 ft diameter aluminum turntable. The graphs shown include the cable loss (which is constant throughout this test) and thus do not represent true site attenuation, but the anomalies measured translate directly to site attenuation curves. Both horizontally and vertically swept site response measurements were made from 20 MHz to 1000 MHz using biconical and log-periodic broadband antennas. A best case was determined by covering the gap between the turntable and ground screen with copper foil tape. This became the reference with which all other measurements were compared. The impedance across the gap between the turntable and the ground plane was measured, using a vector impedance analyzer, to determine any correlation to site anomalies.<>
{"title":"Effect of flush mounted turntables on site attenuation","authors":"D. R. Friesen, V. Flores","doi":"10.1109/NSEMC.1989.37172","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37172","url":null,"abstract":"When performing various electromagnetic emissions tests, rotation of the equipment under test is often accomplished by the use of turntables. The increasing use of flush mounted metal turntables, instead of above-ground nonmetallic turntables, leads to the problem of how to characterize the interface between the metallic turntable and the ground plane. Several different approaches are used to address this problem: ignoring it, single-point grounding, capacitive coupling, and massively parallel grounding. Site attenuation measurements were made at an open-area test site that has a 12 m by 42 m ground screen and an 8 ft diameter aluminum turntable. The graphs shown include the cable loss (which is constant throughout this test) and thus do not represent true site attenuation, but the anomalies measured translate directly to site attenuation curves. Both horizontally and vertically swept site response measurements were made from 20 MHz to 1000 MHz using biconical and log-periodic broadband antennas. A best case was determined by covering the gap between the turntable and ground screen with copper foil tape. This became the reference with which all other measurements were compared. The impedance across the gap between the turntable and the ground plane was measured, using a vector impedance analyzer, to determine any correlation to site anomalies.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121646078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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