A theory based on the average potential method is presented to explain this phenomenon. The analysis of the stable modes shows that it is possible to control the mode by suitable design of the circuit. This active antenna array generates the sum pattern when the two units are connected by a metal strip. Instead of the chip resistor and the metal strip, appropriate devices may be used in the circuit to switch the modes and the radiation pattern can be changed electronically.<>
{"title":"Mode switch in a two-element active array","authors":"J. Lin, T. Itoh, S. Nogi","doi":"10.1109/APS.1993.385259","DOIUrl":"https://doi.org/10.1109/APS.1993.385259","url":null,"abstract":"A theory based on the average potential method is presented to explain this phenomenon. The analysis of the stable modes shows that it is possible to control the mode by suitable design of the circuit. This active antenna array generates the sum pattern when the two units are connected by a metal strip. Instead of the chip resistor and the metal strip, appropriate devices may be used in the circuit to switch the modes and the radiation pattern can be changed electronically.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115665252","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}
The author outlines the causes of PIM (passive intermodulation) measurement techniques, and proven means of PIM reduction. Material and geometry considerations are examined. It is pointed out that PIM is an important consideration in high-channel-capacity communications systems. Ferrite materials and geometries with high current densities show particularly poor PIM performance. Environmental effects often degrade PIM performance. Although results are difficult to quantify, it is concluded that heeding a few basic design recommendations will decrease PIM levels.<>
{"title":"Passive intermodulation considerations in antenna design","authors":"J. Sanford","doi":"10.1109/APS.1993.385516","DOIUrl":"https://doi.org/10.1109/APS.1993.385516","url":null,"abstract":"The author outlines the causes of PIM (passive intermodulation) measurement techniques, and proven means of PIM reduction. Material and geometry considerations are examined. It is pointed out that PIM is an important consideration in high-channel-capacity communications systems. Ferrite materials and geometries with high current densities show particularly poor PIM performance. Environmental effects often degrade PIM performance. Although results are difficult to quantify, it is concluded that heeding a few basic design recommendations will decrease PIM levels.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124405196","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}
Particular attention is given to the design and analysis of compound slot arrays, the design of arrays of hybrid elements, and an array design with three control parameters.<>
重点介绍了复合槽阵的设计与分析、混合单元阵的设计以及具有三个控制参数的阵的设计。
{"title":"Interpolation methods in the design and analysis of slot arrays","authors":"S. Rengarajan","doi":"10.1109/APS.1993.385169","DOIUrl":"https://doi.org/10.1109/APS.1993.385169","url":null,"abstract":"Particular attention is given to the design and analysis of compound slot arrays, the design of arrays of hybrid elements, and an array design with three control parameters.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117110147","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}
A comprehensive symmetry analysis of 2-D clusters with either a square or hexagonal lattice is being performed to determine the dependence of the wave impedance and the propagation constant on the frequency and the azimuthal direction of wave propagation. The boundary conditions for reflection-free, multiport impedance matching around the perimeter of finite clusters are being formally defined. Generalized matrix-algorithms have been derived that formally express the open-circuit impedance matrix of a cluster of finite extent, as seen from the external ports, aligned around the structure perimeter. These algorithms use a multilevel diakoptic approach, by tearing the cluster into progressively smaller subdivisions, while maintaining geometrical similarity, and conserving the translation-, rotation-, and reflection-symmetry of the whole system. Formal expressions have been obtained for the 2-D traveling-wave amplitude and phase patterns generated by any given distribution of mutually coherent excitation sources.<>
{"title":"Symmetry analysis of large two-dimensional clusters of coupled cavity resonators","authors":"R. Speciale","doi":"10.1109/APS.1993.385119","DOIUrl":"https://doi.org/10.1109/APS.1993.385119","url":null,"abstract":"A comprehensive symmetry analysis of 2-D clusters with either a square or hexagonal lattice is being performed to determine the dependence of the wave impedance and the propagation constant on the frequency and the azimuthal direction of wave propagation. The boundary conditions for reflection-free, multiport impedance matching around the perimeter of finite clusters are being formally defined. Generalized matrix-algorithms have been derived that formally express the open-circuit impedance matrix of a cluster of finite extent, as seen from the external ports, aligned around the structure perimeter. These algorithms use a multilevel diakoptic approach, by tearing the cluster into progressively smaller subdivisions, while maintaining geometrical similarity, and conserving the translation-, rotation-, and reflection-symmetry of the whole system. Formal expressions have been obtained for the 2-D traveling-wave amplitude and phase patterns generated by any given distribution of mutually coherent excitation sources.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117118577","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}
A new method for feeding a circular microstrip patch antenna with a 50/spl Omega/ microstrip feed line without causing a deterioration in the antenna radiation characteristics is reported. The input impedance tuning ability of this antenna makes it attractive as a radiating element in large phased arrays implementing a corporate feeding structure. The design consists of a sectoral slot and a shunt element on the circular patch. This structure shows a wide variation in input impedance along the circumference with reference to the slot.<>
{"title":"A new circular patch antenna","authors":"S. Dey, C. Aanandan, P. Mohanan, K. D. Nair","doi":"10.1109/APS.1993.385185","DOIUrl":"https://doi.org/10.1109/APS.1993.385185","url":null,"abstract":"A new method for feeding a circular microstrip patch antenna with a 50/spl Omega/ microstrip feed line without causing a deterioration in the antenna radiation characteristics is reported. The input impedance tuning ability of this antenna makes it attractive as a radiating element in large phased arrays implementing a corporate feeding structure. The design consists of a sectoral slot and a shunt element on the circular patch. This structure shows a wide variation in input impedance along the circumference with reference to the slot.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120985126","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}
An exact formulation for the vector potential and corresponding electric fields associated with a uniform current cylindrical dipole antenna of arbitrary radius is presented. The exact expressions converge rapidly in the induction and near field regions of the antenna. They are completely general and independent of the usual restrictions involving the wavelength, field point distance, dipole radius and length.<>
{"title":"Exact expressions for the vector potential and electric fields of a uniform current cylindrical antenna","authors":"D. Werner, P. Werner","doi":"10.1109/APS.1993.385334","DOIUrl":"https://doi.org/10.1109/APS.1993.385334","url":null,"abstract":"An exact formulation for the vector potential and corresponding electric fields associated with a uniform current cylindrical dipole antenna of arbitrary radius is presented. The exact expressions converge rapidly in the induction and near field regions of the antenna. They are completely general and independent of the usual restrictions involving the wavelength, field point distance, dipole radius and length.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121092260","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}
The author suggests a partitioning scheme to compute the LU decomposition of an augmented moment method matrix rather than the explicit inverse. Basic building blocks which can be computed efficiently, such as bodies of revolution, can be used as starting points for the procedure. The total computational cost with a given known subproblem should then be significantly reduced compared with a direct computation of the LU decomposition of the entire matrix.<>
{"title":"An LU-spatial decomposition method [EM scattering]","authors":"R. Kastner","doi":"10.1109/APS.1993.385212","DOIUrl":"https://doi.org/10.1109/APS.1993.385212","url":null,"abstract":"The author suggests a partitioning scheme to compute the LU decomposition of an augmented moment method matrix rather than the explicit inverse. Basic building blocks which can be computed efficiently, such as bodies of revolution, can be used as starting points for the procedure. The total computational cost with a given known subproblem should then be significantly reduced compared with a direct computation of the LU decomposition of the entire matrix.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127249942","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}
In contrast to a neural network-based synthesis technique proposed by C. H. Chan et al. (1992), the present method does not search for the optimal design by optimizing the dimensions of a given element shape. Instead, such a design is obtained by cascading elementary building blocks of predefined element shapes and dielectric layers. A small database containing 16 different element types is used to illustrate the proposed technique.<>
{"title":"Design of multilayered FSS and waveguide filters using genetic algorithms","authors":"E. Michielssen, J. Sajer, R. Mittra","doi":"10.1109/APS.1993.385586","DOIUrl":"https://doi.org/10.1109/APS.1993.385586","url":null,"abstract":"In contrast to a neural network-based synthesis technique proposed by C. H. Chan et al. (1992), the present method does not search for the optimal design by optimizing the dimensions of a given element shape. Instead, such a design is obtained by cascading elementary building blocks of predefined element shapes and dielectric layers. A small database containing 16 different element types is used to illustrate the proposed technique.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125022063","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}
The authors present simplified, computationally faster, versions of the dielectric-wedge UTD (uniform geometrical theory of diffraction) coefficients for the case of a wedge with one perfectly conducting face. Expressions for several scattering configurations are considered. Included are plane-wave incidence, far-field observation; cylindrical-wave incidence from a finite distance (/spl rho/'), far-field observation; plane-wave incidence, observation at a finite distance (/spl rho/); and surface-wave scattering with the appropriate transition terms. These variations allow one to incorporate higher-order diffraction terms into the analysis of typical, practical target geometries such as a flat plate or dihedral corner reflector. A model for predicting the RCS (radar cross section) of a flat plate coated with an electrically thin, lossy dielectric using the UTD coefficients for a coated half plane is presented.<>
{"title":"Scattering from coated geometries","authors":"L. Polka, C. Balanis","doi":"10.1109/APS.1993.385536","DOIUrl":"https://doi.org/10.1109/APS.1993.385536","url":null,"abstract":"The authors present simplified, computationally faster, versions of the dielectric-wedge UTD (uniform geometrical theory of diffraction) coefficients for the case of a wedge with one perfectly conducting face. Expressions for several scattering configurations are considered. Included are plane-wave incidence, far-field observation; cylindrical-wave incidence from a finite distance (/spl rho/'), far-field observation; plane-wave incidence, observation at a finite distance (/spl rho/); and surface-wave scattering with the appropriate transition terms. These variations allow one to incorporate higher-order diffraction terms into the analysis of typical, practical target geometries such as a flat plate or dihedral corner reflector. A model for predicting the RCS (radar cross section) of a flat plate coated with an electrically thin, lossy dielectric using the UTD coefficients for a coated half plane is presented.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125189709","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}
The authors generalize the analysis of the vertical dipole in the presence of two layers to three layers. The electromagnetic field of a vertical dipole in the presence of a three-layered region has application to radio communication over asphalt- or cement-coated ground, as well as over Arctic ice or ice on a lake. The three-layer analysis provides the field generated by vertical elements in microstrip circuits and antennas. In combination with the field already available for the horizontal electric dipole, it provides the field of magnetic dipoles which are useful in the 10-100 Hz frequency range for detecting submerged submarines in the ocean and under Arctic ice.<>
{"title":"The propagation of electromagnetic waves generated by a vertical electric dipole in the presence of two- and three-layered regions","authors":"R. King, S. Sandler","doi":"10.1109/APS.1993.385322","DOIUrl":"https://doi.org/10.1109/APS.1993.385322","url":null,"abstract":"The authors generalize the analysis of the vertical dipole in the presence of two layers to three layers. The electromagnetic field of a vertical dipole in the presence of a three-layered region has application to radio communication over asphalt- or cement-coated ground, as well as over Arctic ice or ice on a lake. The three-layer analysis provides the field generated by vertical elements in microstrip circuits and antennas. In combination with the field already available for the horizontal electric dipole, it provides the field of magnetic dipoles which are useful in the 10-100 Hz frequency range for detecting submerged submarines in the ocean and under Arctic ice.<<ETX>>","PeriodicalId":138141,"journal":{"name":"Proceedings of IEEE Antennas and Propagation Society International Symposium","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125269186","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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