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National Symposium on Electromagnetic Compatibility最新文献

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Antenna beamwidth considerations 天线波束宽度的考虑
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37215
R.P. Trefney
{"title":"Antenna beamwidth considerations","authors":"R.P. Trefney","doi":"10.1109/NSEMC.1989.37215","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37215","url":null,"abstract":"An empirical investigation is described in which the author studied antenna beamwidth of radiation and how it contributes to errors in the measurement of radiated profiles due to the antenna's directivity. These errors result because measurements are often taken using highly directional antennas that tend to mask the full measurement amplitude of the equipment under test (EUT) due to the antenna's directivity. Errors from this oversight may cause units to appear within prescribed radiation limits when in fact they may be falling. The author suggests that either a variable test distance be used to accommodate the beamwidth of the given antenna or some fixed distance which would adequately include the narrowest beamwidth that would be used, thereby allowing the measurement antenna to illuminate the EUT fully. He further suggests that all measurements be conducted on bore sight with respect to the EUT as seen by the measurement antenna.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"609 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":"123262527","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}
引用次数: 0
Calculation of energy in transient overvoltages 瞬态过电压的能量计算
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37183
R. B. Standler
{"title":"Calculation of energy in transient overvoltages","authors":"R. B. Standler","doi":"10.1109/NSEMC.1989.37183","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37183","url":null,"abstract":"It is argued that the calculation of the energy in a transient overvoltage using the time integral of V/sup 2/(t)/Z, where Z has the default value of 50 Omega and the voltage, V(t), is that between the hot conductor in the AC line and ground, is inaccurate. A quantitative error analysis is presented that uses an artificial AC line network to simulate a long branch circuit and to give the impedance of the AC line as a function of frequency. A method for measuring energy dissipated in a varistor is advocated for use in future experiments. While measuring the energy in a varistor avoids many of the problems associated with the overvoltage energy, the energy dissipated in a varistor is also an underestimate of the total energy in the transient overvoltage.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"7 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":"126449151","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}
引用次数: 10
Photonic probes for the measurement of electromagnetic fields over broad bandwidths 用于测量宽频带上电磁场的光子探针
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37139
K. Masterson, L. D. Driver, M. Kanda
{"title":"Photonic probes for the measurement of electromagnetic fields over broad bandwidths","authors":"K. Masterson, L. D. Driver, M. Kanda","doi":"10.1109/NSEMC.1989.37139","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37139","url":null,"abstract":"The characteristics of photonic systems that make them especially well suited for use as broadband electromagnetic (EM) field sensors are discussed. Transfer functions are given for the individual components of such a measurement system, with special emphasis given to those of Pockels-cell and modified-directional-coupler optical modulators. An isotropic electric-field meter having 15-cm resistively tapered dipole elements combined with bulk crystal, Pockels-cell modulators is described. The meter's frequency response is flat between 30 kHz and 100 MHz, except for resonances in the modulator crystals that occur between 1 and 10 MHz. For a 3-kHz detection bandwidth, the noise floor is equivalent to a field of about 7 V/m, and the calculated linear dynamic range is 70 dB in EM-field power density. The response is within +or-2 dB of the ideal isotropic response. A photonic probe that uses a modified directional-coupler modulator is briefly described.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"58 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":"134623757","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}
引用次数: 23
Radio system interference analysis and computation method for two co-sited broadband transceivers 两台共址宽带收发机无线电系统干扰分析与计算方法
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37223
J. Gavan
{"title":"Radio system interference analysis and computation method for two co-sited broadband transceivers","authors":"J. Gavan","doi":"10.1109/NSEMC.1989.37223","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37223","url":null,"abstract":"A qualitative analysis is presented of mutual interference arising when two perfectly shielded transceivers, sited at the same location, are operating simultaneously. The restrictions imposed on the antennas for achieving reliable operation of a third remote system victim receiver are also considered. In addition, some recently developed semiempirical, computer methods are discussed that allow the mutual interference factors affecting several worst-case scenarios to be computed. These computed results are then used to check design modifications and to improve system operational performance, including frequency management.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"704 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":"132191746","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}
引用次数: 0
A method for identifying EMI critical circuits during development of a large C3 一种在大型C3开发过程中识别EMI关键电路的方法
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37153
D. Barr
{"title":"A method for identifying EMI critical circuits during development of a large C3","authors":"D. Barr","doi":"10.1109/NSEMC.1989.37153","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37153","url":null,"abstract":"The circuit analysis methods and process Boeing Aerospace used on a large, ground-based military command, control, and communications (C/sup 3/) system are described. This analysis was designed to help identify electromagnetic interference (EMI) critical circuits. The methodology used the MIL-E-6051 equipment criticality categories as the basis for defining critical circuits, relational database technology to help sort through and account for all of the approximately 5000 system signal cables, and Macintosh Plus personal computers to predict critical circuits based on safety margin analysis. The EMI circuit analysis process systematically examined all system circuits to identify which ones were likely to be EMI critical. The process used two separate, sequential safety margin analyses to identify critical circuits (conservative safety margin analysis, and detailed safety margin analysis). These analyses used field-to-wire and wire-to-wire coupling models using both worst-case and detailed circuit parameters (physical and electrical) to predict circuit safety margins. This process identified the predicted critical circuits that could then be verified by test.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"130 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":"115081128","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}
引用次数: 0
Improved low-frequency performance of pyramid-cone absorbers for application in semi-anechoic chambers 半消声室锥体吸波器低频性能的改进
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37217
E. Kuester, Christopher L. Holloway, Electromagnetics
{"title":"Improved low-frequency performance of pyramid-cone absorbers for application in semi-anechoic chambers","authors":"E. Kuester, Christopher L. Holloway, Electromagnetics","doi":"10.1109/NSEMC.1989.37217","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37217","url":null,"abstract":"A mathematical model, developed by the authors to describe the low-frequency reflection properties of arrays of pyramid-cone absorbers, is used to improve the design of these cones in the range of 30 to 300 MHz. The model shows that at frequencies such that the transverse spacing of the cones is small compared to a wavelength, a reflecting wave is not influenced by the individual cones, but rather the wave is acted upon as if only a one-dimensionally layered, anisotropic equivalent medium exists, whose parameters depend on the geometry and electrical composition of the cones. It is thus possible using elementary means to calculate the reflection coefficient of an arbitrarily polarized and incident plane wave from an array of these cones and hence to assess their performance in an anechoic chamber. Results of the application of this design to semianechoic measurement chambers are presented. These are found to provide closer correlation to the site attenuation curves for an ideal open-field test site.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"46 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":"116726520","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}
引用次数: 19
A method for interlaboratory stripline susceptibility test calibration 一种实验室间带线药敏试验校准方法
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37158
K. Williams
{"title":"A method for interlaboratory stripline susceptibility test calibration","authors":"K. Williams","doi":"10.1109/NSEMC.1989.37158","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37158","url":null,"abstract":"A method is presented for correlating susceptibility tests between two different electromagnetic compatibility (EMC) laboratories using stripline antenna test methods by utilizing similar test antennas. A controlled test antenna is used along with swept frequency techniques to gather data rapidly which are then used to correlate results from two or more laboratories or to locate and eliminate the causes of variation between laboratories. If differences in the two sets of measurements cannot be eliminated, these results can be used to provide a quantitative prediction of the differences between the test results to be expected between the two laboratories. The advantage of this approach is that the device under test in this case is passive, uniform, and easily duplicated in different laboratories and does not have many of the disadvantages associated with transporting a generic active device under test from one laboratory to another. The method can be used as a periodic check on the performance of the test system since each laboratory can easily possess its own standard antenna.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"48 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":"134212200","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}
引用次数: 0
Effects of corrosion on the electrical properties of conducted finishes for EMI shielding 腐蚀对电磁干扰屏蔽用导电涂层电性能的影响
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37149
B. Archambeault, R. Thibeau
{"title":"Effects of corrosion on the electrical properties of conducted finishes for EMI shielding","authors":"B. Archambeault, R. Thibeau","doi":"10.1109/NSEMC.1989.37149","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37149","url":null,"abstract":"A variety of combinations of fingerstock materials both before and after exposure to an accelerated atmospheric corrosion environment was tested. The following materials/finishes were tested during this study: 304 stainless steel, passivated, MIL STD QQ-P-35B; 1010 steel, electroplated bright tin, 0.0003 in. nominal coating thickness, ASTM B545; 1010 steel, electroplated nickel 0.0005 in. nominal coating thickness, ASTMB689; 1010 steel, electroless nickel, 0.0005 in. coating thickness; 1010 steel, zinc-plated, 0.0005 in. plating thickness with yellow chromate conversion coating; 1010 steel, zinc-plated, 0.0002 in. minimum zinc thickness, with blue-bright chromate conversion coating; electrogalvanized steel, 0.0007 in. zinc thickness, with yellow chromate conversion coating; steel with hot-dipped aluminum-zinc (55:45) coating, 0.0008 in. coating thickness; 5052 aluminum, with yellow chromate conversion coating; and 5052 aluminum, with clear chromate conversion coating, ASTM B449, class 3. Metal panels were mated with beryllium copper fingerstock to make the joints typical of computer enclosure doors and panels. The finishes on the beryllium copper were: electroplated bright tin; electroplated bright nickel; electroplated tin-lead (60:40); and bright dip (a thin chromated conversion coating). The transfer impedance of the joint was used to measure the electrical performance and then the corrosion resistance of the conductive finishes.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"70 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":"122048567","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}
引用次数: 6
Congruence of low voltage power main transient designs 低压电力主暂态设计的一致性
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37194
W. Rhoades
{"title":"Congruence of low voltage power main transient designs","authors":"W. Rhoades","doi":"10.1109/NSEMC.1989.37194","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37194","url":null,"abstract":"It is argued that the conditions and problems for high-voltage protection in the 1920s to 1940s are similar to those prevailing today for low-voltage (under 1000 V RMS) power system transient protection. Data are now being collected beyond voltage crest values vs. occurrence rate such as: waveshape epoch, rate of rise, ringing periods, energy, and energy spectral density. Protection design is complicated by the wide diversity of equipment designs which are installed, differing site conditions, and the effects of load on the power main distribution with transients ranging from electrically fast nanosecond duration to very long duration. Since no present standard can adequately test for these transients, low-voltage transient protection standards are being revised. The updating of the database and equipment testing can result in better cost-effective surge protection.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"48 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":"130044442","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}
引用次数: 5
The effect of duty cycle on SMPS common mode emissions: theory and experiment 占空比对SMPS共模发射的影响:理论与实验
National Symposium on Electromagnetic Compatibility Pub Date : 1989-05-23 DOI: 10.1109/NSEMC.1989.37182
M. Nave
{"title":"The effect of duty cycle on SMPS common mode emissions: theory and experiment","authors":"M. Nave","doi":"10.1109/NSEMC.1989.37182","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37182","url":null,"abstract":"The theoretical time- and frequency-domain waveforms of common-mode conducted emissions are derived for a switched mode power supply (SMPS) of arbitrary duty cycle. The dependence of common-mode emissions on duty cycle and switching frequency is derived, modeled, and verified through experimental data. A special fly-back converter was built to isolate the switching transistor heat-sink parasitic capacitance from other potential sources. Data on the common-mode emissions from this source were taken utilizing the line impedance stabilization network measurement method. Time-domain and frequency-domain data were taken for different supply operation parameters (states). The varying common-mode emissions of the supply were compared to that predicted by an earlier model. The magnitudes of the common-mode emissions are shown to be independent of switching transistor risetime. Using Fourier analysis of the common-mode waveform, the model predicts the variation of emissions with duty cycle value.<<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":"129920880","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}
引用次数: 18
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