Pub Date : 1996-08-19DOI: 10.1109/ISEMC.1996.561253
D. Moongilan
It is a well known skin effect that in a coaxial cable differential current flows on the outer surface of the center conductor and inner surface of the shield. In cylindrical conductors, if the current density is axial, the flux density is always tangential at any radius within the conductor. In flat parallel conductors of finite thickness, the high frequency current flows within the inner surfaces of the conductors for very small conductor separation. If the conductor separation is larger, the field distribution on the conductors is very similar to that of isolated conductors and current flows on both inner and outer surfaces of both conductors. In this paper, the flat parallel conductor skin effect theory has been applied to backplanes. An outer layer of a backplane and a metallic cover on a backplane have been modeled as one of the parallel conductors and radiated and conducted emissions are analyzed.
{"title":"Skin-effect modeling of radiated emissions from backplanes","authors":"D. Moongilan","doi":"10.1109/ISEMC.1996.561253","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561253","url":null,"abstract":"It is a well known skin effect that in a coaxial cable differential current flows on the outer surface of the center conductor and inner surface of the shield. In cylindrical conductors, if the current density is axial, the flux density is always tangential at any radius within the conductor. In flat parallel conductors of finite thickness, the high frequency current flows within the inner surfaces of the conductors for very small conductor separation. If the conductor separation is larger, the field distribution on the conductors is very similar to that of isolated conductors and current flows on both inner and outer surfaces of both conductors. In this paper, the flat parallel conductor skin effect theory has been applied to backplanes. An outer layer of a backplane and a metallic cover on a backplane have been modeled as one of the parallel conductors and radiated and conducted emissions are analyzed.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125888208","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561260
J. Quine, C. Brown, K. Fisher, J.P. Streeter, A. Pesta
This paper discusses the experimental characterization at microwave frequencies of leakage sources such as gasketed seams and attenuating cover panels by methods that employ a reverberation chamber (REVCH) to measure the total power radiated into the REVCH by the leakage source. The preferred characterization of a leakage source is in terms of the effective transmission area (ETA) defined as the total radiated leakage power (watts) divided by the microwave flux (watts per square meter) incident on the leakage source from outside the REVCH. Several sources of error that can occur in measuring ETA are identified, non-uniformities in material and cross-sectional dimensions of the test panel or gasket being a significant source of error. The non-uniformities can result in "hot spots" which have unknown size and position along the length of a gasket or over the area of a panel, and therefore, can have uncertain power coupling into the REVCH. The results presented in this paper indicate clearly the need to further modify MIL-STD-285 to include a requirement for some form of mode stirring. Furthermore, "ETA" should be adopted as a preferred characterization for the microwave shielding performance of gaskets and cover panels.
{"title":"Testing of microwave shielding gaskets and cover panels-recent work at Rome Laboratories","authors":"J. Quine, C. Brown, K. Fisher, J.P. Streeter, A. Pesta","doi":"10.1109/ISEMC.1996.561260","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561260","url":null,"abstract":"This paper discusses the experimental characterization at microwave frequencies of leakage sources such as gasketed seams and attenuating cover panels by methods that employ a reverberation chamber (REVCH) to measure the total power radiated into the REVCH by the leakage source. The preferred characterization of a leakage source is in terms of the effective transmission area (ETA) defined as the total radiated leakage power (watts) divided by the microwave flux (watts per square meter) incident on the leakage source from outside the REVCH. Several sources of error that can occur in measuring ETA are identified, non-uniformities in material and cross-sectional dimensions of the test panel or gasket being a significant source of error. The non-uniformities can result in \"hot spots\" which have unknown size and position along the length of a gasket or over the area of a panel, and therefore, can have uncertain power coupling into the REVCH. The results presented in this paper indicate clearly the need to further modify MIL-STD-285 to include a requirement for some form of mode stirring. Furthermore, \"ETA\" should be adopted as a preferred characterization for the microwave shielding performance of gaskets and cover panels.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127897891","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561235
F. Leferink
Methods to measure the ground lift voltage are described. From this voltage the ground impedance can be determined. The ground impedance is equal to the DC resistance for low frequencies. However, for high frequencies the ground impedance is determined by the external inductance, and, if this external inductance is very small, by the AC resistance too. The obtained inductance figures are compared with theoretical values. PC board transmission lines are discussed in particular.
{"title":"Inductance calculations; experimental investigations","authors":"F. Leferink","doi":"10.1109/ISEMC.1996.561235","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561235","url":null,"abstract":"Methods to measure the ground lift voltage are described. From this voltage the ground impedance can be determined. The ground impedance is equal to the DC resistance for low frequencies. However, for high frequencies the ground impedance is determined by the external inductance, and, if this external inductance is very small, by the AC resistance too. The obtained inductance figures are compared with theoretical values. PC board transmission lines are discussed in particular.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"os-35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127979432","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561420
Y. Ohba, R. Sato, Y. Nemoto
Filters are widely used in communication systems and EMC equipment. We consider about the mixed lumped and nonuniform distributed circuit band-pass filter using nonuniform transmission line (NTL-PR) represented with lumped parallel resonance circuit, uniform transmission line and lumped /spl pi/-type Brune section with negative sign. First, the simple equivalent circuit of the NTL-PR is shown. It can be represented with an imaginary gyrator and a lumped capacitor. Next, the design method for the mixed lumped and nonuniform distributed circuit band-pass filter is shown. The design method uses the simple equivalent circuit. Finally, examples of the transmission characteristics of the band-pass filters are shown.
{"title":"The mixed lumped and nonuniform distributed circuit band-pass filter","authors":"Y. Ohba, R. Sato, Y. Nemoto","doi":"10.1109/ISEMC.1996.561420","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561420","url":null,"abstract":"Filters are widely used in communication systems and EMC equipment. We consider about the mixed lumped and nonuniform distributed circuit band-pass filter using nonuniform transmission line (NTL-PR) represented with lumped parallel resonance circuit, uniform transmission line and lumped /spl pi/-type Brune section with negative sign. First, the simple equivalent circuit of the NTL-PR is shown. It can be represented with an imaginary gyrator and a lumped capacitor. Next, the design method for the mixed lumped and nonuniform distributed circuit band-pass filter is shown. The design method uses the simple equivalent circuit. Finally, examples of the transmission characteristics of the band-pass filters are shown.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"223 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129932585","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561256
P. Kistenmacher, A. Schwab
This paper presents a two dimensional analytical solution for electromagnetic shielding problems at frequencies below resonances. The application of the method to three dimensional shields yields good approximations, except for errors nearby edges which are not parallel to the magnetic field. The solution is valid for enclosures of arbitrary shape with any given combination of materials and wall thicknesses. Considering skin effects, the shielding effectiveness is derived by solving the Helmholtz equation for individual parts of the wall with different thicknesses and materials. The solution for the total shield is then found by applying Faraday's law in integral form. Three cases are discussed: heterogeneous enclosures consisting of several wall sections with different materials and wall thicknesses, coated, laminated and nested shields and multi-cavity enclosures. Different examples of combinations of non-magnetic and magnetic materials are discussed in detail. Finally, the potential of saving material and weight by using multiple shields is investigated.
{"title":"Low-frequency shielding effectiveness of inhomogeneous enclosures","authors":"P. Kistenmacher, A. Schwab","doi":"10.1109/ISEMC.1996.561256","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561256","url":null,"abstract":"This paper presents a two dimensional analytical solution for electromagnetic shielding problems at frequencies below resonances. The application of the method to three dimensional shields yields good approximations, except for errors nearby edges which are not parallel to the magnetic field. The solution is valid for enclosures of arbitrary shape with any given combination of materials and wall thicknesses. Considering skin effects, the shielding effectiveness is derived by solving the Helmholtz equation for individual parts of the wall with different thicknesses and materials. The solution for the total shield is then found by applying Faraday's law in integral form. Three cases are discussed: heterogeneous enclosures consisting of several wall sections with different materials and wall thicknesses, coated, laminated and nested shields and multi-cavity enclosures. Different examples of combinations of non-magnetic and magnetic materials are discussed in detail. Finally, the potential of saving material and weight by using multiple shields is investigated.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130333442","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561211
A. Cangellaris
This paper provides a critical review of frequency-domain finite element methods and their applications to the modeling of electromagnetic interactions in complex electronic components and systems. Emphasis is placed on the latest advances in finite element grid generation practices, element interpolation function selection, and robust, highly absorbing numerical grid truncation techniques for modeling electromagnetic interactions in unbounded domains. These advances have helped enhance the robustness and accuracy of the method. Finally, the advantages of domain decomposition techniques for the modeling of complex geometries are examined. Such domain decomposition techniques are expected to play an important role in the continuing effort to extend the applications of frequency-domain finite methods beyond the subcomponent-level to component and system modeling for electromagnetic interference and electromagnetic compatibility analysis and design.
{"title":"Frequency-domain finite element methods for electromagnetic field simulation: fundamentals, state of the art, and applications to EMI/EMC analysis","authors":"A. Cangellaris","doi":"10.1109/ISEMC.1996.561211","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561211","url":null,"abstract":"This paper provides a critical review of frequency-domain finite element methods and their applications to the modeling of electromagnetic interactions in complex electronic components and systems. Emphasis is placed on the latest advances in finite element grid generation practices, element interpolation function selection, and robust, highly absorbing numerical grid truncation techniques for modeling electromagnetic interactions in unbounded domains. These advances have helped enhance the robustness and accuracy of the method. Finally, the advantages of domain decomposition techniques for the modeling of complex geometries are examined. Such domain decomposition techniques are expected to play an important role in the continuing effort to extend the applications of frequency-domain finite methods beyond the subcomponent-level to component and system modeling for electromagnetic interference and electromagnetic compatibility analysis and design.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133713097","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561208
S. Seker, B. Altay
Electromagnetic propagation through curved surface is important in the area of shielding for the design of the proper shield. The radar cross section is the only important parameter in determining the electromagnetic shielding properties of surfaces. The radar cross sections of a dielectric thin curved surface are obtained by employing a quasi-static approximation. The results are complemented by numerical calculations and their validity are presented by comparison with available exact results in literature. Excellent agreement is found for horizontal and vertical polarization.
{"title":"Shielding properties of thin curved surfaces","authors":"S. Seker, B. Altay","doi":"10.1109/ISEMC.1996.561208","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561208","url":null,"abstract":"Electromagnetic propagation through curved surface is important in the area of shielding for the design of the proper shield. The radar cross section is the only important parameter in determining the electromagnetic shielding properties of surfaces. The radar cross sections of a dielectric thin curved surface are obtained by employing a quasi-static approximation. The results are complemented by numerical calculations and their validity are presented by comparison with available exact results in literature. Excellent agreement is found for horizontal and vertical polarization.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134040169","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561418
C. Kraft, B. Banner
A method is presented to compute the variable Edmax (maximum electric field) used in antenna calibration and site attenuation from a method of moments simulation. The method is especially useful for directional antennas such as log periodics where the dipole assumptions incorporated into the Edmax tables of ANSI C63.5 may not be adequate.
{"title":"Selection of the variable Edmax in calibration of log periodic antennas","authors":"C. Kraft, B. Banner","doi":"10.1109/ISEMC.1996.561418","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561418","url":null,"abstract":"A method is presented to compute the variable Edmax (maximum electric field) used in antenna calibration and site attenuation from a method of moments simulation. The method is especially useful for directional antennas such as log periodics where the dipole assumptions incorporated into the Edmax tables of ANSI C63.5 may not be adequate.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123109260","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561214
A. Ruehli
The PEEC approach is a full wave electromagnetic electrical modeling technique for conductors embedded in arbitrary dielectrics in terms of equivalent circuits. The basic formulation is an electric field integral equation (EFIE) full wave solution to Maxwell's equations. The models can be used in both the time as well as the frequency domain. It facilitates the solution of problems which have both an electromagnetic part as well as a circuit part. Also, it leads to an intuitive understanding of electromagnetic problems.
{"title":"Partial element equivalent circuit (PEEC) method and its application in the frequency and time domain","authors":"A. Ruehli","doi":"10.1109/ISEMC.1996.561214","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561214","url":null,"abstract":"The PEEC approach is a full wave electromagnetic electrical modeling technique for conductors embedded in arbitrary dielectrics in terms of equivalent circuits. The basic formulation is an electric field integral equation (EFIE) full wave solution to Maxwell's equations. The models can be used in both the time as well as the frequency domain. It facilitates the solution of problems which have both an electromagnetic part as well as a circuit part. Also, it leads to an intuitive understanding of electromagnetic problems.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114490412","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 : 1996-08-19DOI: 10.1109/ISEMC.1996.561217
H. Anzai, T. Kishimoto, T. Yamazaki, Y. Naito, T. Mizumoto
A semi-anechoic chamber is known to be useful for EMC measurements in a frequency range from 30 MHz to 1000 MHz. The analysis using a ray-tracing technique is investigated to evaluate a normalized site attenuation in the semi-anechoic chamber which is used for EMC measurements in a 3 m or 10 m method. The validity of the analysis is verified for a chamber lined with a multi-layer ferrite absorber by comparison with experimental data. The analysis is also applied to estimate the thickness of pyramidal absorber required to satisfy the ANSI standard.
{"title":"Analysis of semi-anechoic chamber using ray-tracing technique","authors":"H. Anzai, T. Kishimoto, T. Yamazaki, Y. Naito, T. Mizumoto","doi":"10.1109/ISEMC.1996.561217","DOIUrl":"https://doi.org/10.1109/ISEMC.1996.561217","url":null,"abstract":"A semi-anechoic chamber is known to be useful for EMC measurements in a frequency range from 30 MHz to 1000 MHz. The analysis using a ray-tracing technique is investigated to evaluate a normalized site attenuation in the semi-anechoic chamber which is used for EMC measurements in a 3 m or 10 m method. The validity of the analysis is verified for a chamber lined with a multi-layer ferrite absorber by comparison with experimental data. The analysis is also applied to estimate the thickness of pyramidal absorber required to satisfy the ANSI standard.","PeriodicalId":296175,"journal":{"name":"Proceedings of Symposium on Electromagnetic Compatibility","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122367007","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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