The fields scattered by a finite dielectric wedge are computed, and the results obtained by using two different integral equations are compared. The unknown boundary function is either the jump eta in the normal derivative of the auxiliary field across the boundary or the jump phi in the field itself. In the latter case, one of the integrals is hypersingular. The results obtained using the two different methods are compared for a 90 degrees dielectric wedge terminated by a matching cylindrical surface. The numerical experiments indicate that the results obtained by the two quite different integral equations agree reasonably well, and it is concluded that disagreements with the static limit probably are real, that is, not due to errors in the calculations. The hypersingular integral equation may provide more accurate results because the unknown boundary function does not diverge at the edge of the wedge, although the integrals are more singular.<>
{"title":"The hypersingular single integral equation and the dielectric wedge","authors":"E. Marx","doi":"10.1109/APS.1992.221710","DOIUrl":"https://doi.org/10.1109/APS.1992.221710","url":null,"abstract":"The fields scattered by a finite dielectric wedge are computed, and the results obtained by using two different integral equations are compared. The unknown boundary function is either the jump eta in the normal derivative of the auxiliary field across the boundary or the jump phi in the field itself. In the latter case, one of the integrals is hypersingular. The results obtained using the two different methods are compared for a 90 degrees dielectric wedge terminated by a matching cylindrical surface. The numerical experiments indicate that the results obtained by the two quite different integral equations agree reasonably well, and it is concluded that disagreements with the static limit probably are real, that is, not due to errors in the calculations. The hypersingular integral equation may provide more accurate results because the unknown boundary function does not diverge at the edge of the wedge, although the integrals are more singular.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"193 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122019931","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 alternative method is proposed for measuring the relative effect of mutual coupling on arrays. A smoothness measure of the excitation vector is defined that can be used to find that particular excitation among several possibilities which is least susceptible to mutual coupling. Hence, in synthesis algorithms where more than one excitation vector satisfies the requirements desired, the smoothness measure can be used to find the excitation which implies minimum mutual coupling effects. Results on some simple linear arrays are shown to provide an indication of the behavior of the smoothness index.<>
{"title":"A smoothness measure for antenna pattern synthesis","authors":"J. Richie","doi":"10.1109/APS.1992.221729","DOIUrl":"https://doi.org/10.1109/APS.1992.221729","url":null,"abstract":"An alternative method is proposed for measuring the relative effect of mutual coupling on arrays. A smoothness measure of the excitation vector is defined that can be used to find that particular excitation among several possibilities which is least susceptible to mutual coupling. Hence, in synthesis algorithms where more than one excitation vector satisfies the requirements desired, the smoothness measure can be used to find the excitation which implies minimum mutual coupling effects. Results on some simple linear arrays are shown to provide an indication of the behavior of the smoothness index.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122172659","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 describe a novel active radiating module in which an FET source is integrated with a multilayer slot coupled patch antenna. A design procedure is given and the performance of an X-band prototype circuit is described. Prototype circuits showed 4.81-mW power output and 50-MHz tuning range at 4.893 GHz. The initial results suggest that this device has potential for use in low-cost transmitters, active arrays, spatial power combiners and quasi-optical combiners.<>
{"title":"Active radiating element using FET source integrated with a multilayer slot coupled patch antenna","authors":"Ying Shen, R. Fralich, Chen Wu, J. Litva","doi":"10.1109/APS.1992.221590","DOIUrl":"https://doi.org/10.1109/APS.1992.221590","url":null,"abstract":"The authors describe a novel active radiating module in which an FET source is integrated with a multilayer slot coupled patch antenna. A design procedure is given and the performance of an X-band prototype circuit is described. Prototype circuits showed 4.81-mW power output and 50-MHz tuning range at 4.893 GHz. The initial results suggest that this device has potential for use in low-cost transmitters, active arrays, spatial power combiners and quasi-optical combiners.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117121158","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}
One of the promising methods for improvement of radio astronomy image forming systems is the method of analytical continuation of the object spatial spectrum. However, atmospheric turbulence and internal system noises restrict the real resolution of this method. In the present work, the authors propose that the analytical continuation method be supplemented by such effective noise suppression means as statistical signal processing utilizing triple correlation functions and their Fourier spectra which are called bispectra. The most important advantage of the triple correlation function is its virtual insensitivity to Gaussian noise.<>
{"title":"High-resolution image forming with bispectral data processing","authors":"A. Totsky, V. Morozov","doi":"10.1109/APS.1992.221574","DOIUrl":"https://doi.org/10.1109/APS.1992.221574","url":null,"abstract":"One of the promising methods for improvement of radio astronomy image forming systems is the method of analytical continuation of the object spatial spectrum. However, atmospheric turbulence and internal system noises restrict the real resolution of this method. In the present work, the authors propose that the analytical continuation method be supplemented by such effective noise suppression means as statistical signal processing utilizing triple correlation functions and their Fourier spectra which are called bispectra. The most important advantage of the triple correlation function is its virtual insensitivity to Gaussian noise.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117242119","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 Kirchhoff scalar diffraction integral and the image method are used to investigate the close-in sidelobe performance of the simple and phase reversal circular zone plate antennas. It is found that, with fixed aperture dimension, the sidelobe level of a zone plate antenna depends mainly on N, the number of full wave zones composing the plate. When the aperture field taper is kept constant, the sidelobe level of the zone plate decreases significantly when N increases. This means that, with a given zone plate diameter, a small F/D is favorable for obtaining low close-in sidelobes. For a simple zone plate antenna, adequately lowering the edge illumination intensity does reduce the sidelobe level of a centrally opaque version, but it may raise the sidelobes of a centrally transparent one. For the phase reversal zone plate antenna, it is observed that versions with a central disk and a central aperture yield very similar radiation patterns with sidelobes lower than those of the corresponding simple zone plates. Adequately decreasing the edge illumination level produces lower close-in sidelobes.<>
{"title":"On the sidelobe performance of Fresnel zone plate antennas","authors":"Y.J. Guo, S. Barton","doi":"10.1109/APS.1992.221434","DOIUrl":"https://doi.org/10.1109/APS.1992.221434","url":null,"abstract":"The Kirchhoff scalar diffraction integral and the image method are used to investigate the close-in sidelobe performance of the simple and phase reversal circular zone plate antennas. It is found that, with fixed aperture dimension, the sidelobe level of a zone plate antenna depends mainly on N, the number of full wave zones composing the plate. When the aperture field taper is kept constant, the sidelobe level of the zone plate decreases significantly when N increases. This means that, with a given zone plate diameter, a small F/D is favorable for obtaining low close-in sidelobes. For a simple zone plate antenna, adequately lowering the edge illumination intensity does reduce the sidelobe level of a centrally opaque version, but it may raise the sidelobes of a centrally transparent one. For the phase reversal zone plate antenna, it is observed that versions with a central disk and a central aperture yield very similar radiation patterns with sidelobes lower than those of the corresponding simple zone plates. Adequately decreasing the edge illumination level produces lower close-in sidelobes.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124501256","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}
Boundary conditions of a rectangular cylinder are investigated in the finite-difference time domain for 2-D transverse magnetic (TM) waves. The scheme used is the scheme first proposed by R.H. Ni (1982) as a finite-volume scheme but which can also be viewed as a finite-difference scheme a la Lax-Wendroff. This scheme is solved on a computational, cell-by-cell basis and contains both the electric and magnetic field components at each node, including the corners of the scatterer. Due to the presence of an H-field singularity at the corner, there must be some treatment of the components placed there. To address this problem, images are introduced inside the cylinder to satisfy the boundary conditions and obtain nonzero H-field values on the corner. The results show good agreement with theory with the image corners, in place. The use of images for treatment of the singularity, while not giving the exact solution at the corner (which is not possible), gives very good surface current values which are quite close to the theoretical, a single grid point from the corner.<>
{"title":"Numerical reflecting boundary conditions and treatment of edge singularities for electromagnetic diffraction in the time domain","authors":"M. White, J.J. Chattot","doi":"10.1109/APS.1992.221931","DOIUrl":"https://doi.org/10.1109/APS.1992.221931","url":null,"abstract":"Boundary conditions of a rectangular cylinder are investigated in the finite-difference time domain for 2-D transverse magnetic (TM) waves. The scheme used is the scheme first proposed by R.H. Ni (1982) as a finite-volume scheme but which can also be viewed as a finite-difference scheme a la Lax-Wendroff. This scheme is solved on a computational, cell-by-cell basis and contains both the electric and magnetic field components at each node, including the corners of the scatterer. Due to the presence of an H-field singularity at the corner, there must be some treatment of the components placed there. To address this problem, images are introduced inside the cylinder to satisfy the boundary conditions and obtain nonzero H-field values on the corner. The results show good agreement with theory with the image corners, in place. The use of images for treatment of the singularity, while not giving the exact solution at the corner (which is not possible), gives very good surface current values which are quite close to the theoretical, a single grid point from the corner.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125882306","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}
R. Lenormand, B. Coulomb, C. Feat, C. Rigal, Y. Roussin, B. Vidal St. Andre, C. Villemur
In order to replace a large phased array, antenna subsystems usually combine a large reflector, a small phased array, and an arrangement of small reflectors, which form a large image of the array over the main reflector aperture. This way one can get a large-aperture electronically steerable antenna, using only a small phased array. The basic idea of such an antenna is to use the two offset fed paraboloidal reflectors in such a way that the off-axis aberrations tend to cancel each other. The implementation of a correcting lens in the common focal plane is proposed. The objective is to enlarge the off-axis aberration matching domain, so that the scanning capability is increased (15 beamwidth/40 beamwidth). As an application, a Ka-band mission is discussed for a 3-m-diameter antenna (26 GHz) with a field of view of +or-10 degrees as required for the Data Relay Satellite. It is confirmed that the scanning limitation of the offset fed Gregorian antenna has been relaxed from approximately 15 beamwidth to 40 beamwidth by the use of a corrective lens implemented in the common focal area.<>
{"title":"Large angular electronic beam steering antenna for space application","authors":"R. Lenormand, B. Coulomb, C. Feat, C. Rigal, Y. Roussin, B. Vidal St. Andre, C. Villemur","doi":"10.1109/APS.1992.222021","DOIUrl":"https://doi.org/10.1109/APS.1992.222021","url":null,"abstract":"In order to replace a large phased array, antenna subsystems usually combine a large reflector, a small phased array, and an arrangement of small reflectors, which form a large image of the array over the main reflector aperture. This way one can get a large-aperture electronically steerable antenna, using only a small phased array. The basic idea of such an antenna is to use the two offset fed paraboloidal reflectors in such a way that the off-axis aberrations tend to cancel each other. The implementation of a correcting lens in the common focal plane is proposed. The objective is to enlarge the off-axis aberration matching domain, so that the scanning capability is increased (15 beamwidth/40 beamwidth). As an application, a Ka-band mission is discussed for a 3-m-diameter antenna (26 GHz) with a field of view of +or-10 degrees as required for the Data Relay Satellite. It is confirmed that the scanning limitation of the offset fed Gregorian antenna has been relaxed from approximately 15 beamwidth to 40 beamwidth by the use of a corrective lens implemented in the common focal area.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125993239","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}
Laboratory W-band measurements of the bistatic scattering function of some common microwave absorbing structures have been made. The structures investigated include periodic wedge-type and pyramid-type iron-epoxy calibration loads and flat carbon-foam 'Echosorb' samples. Measurements were made using an HP 8510 network analyzer interfaced with a focused-lens scattering range. The test set provided a dynamic range of approximately 55 dB. Swept frequency measurements over the 75-100-GHz band have revealed specular and Bragg reflection characteristics in the measured data.<>
{"title":"Electromagnetic scattering from microwave absorbers: Laboratory verification of the coupled wave theory","authors":"A. Gasiewski, D. Jackson","doi":"10.1109/APS.1992.221911","DOIUrl":"https://doi.org/10.1109/APS.1992.221911","url":null,"abstract":"Laboratory W-band measurements of the bistatic scattering function of some common microwave absorbing structures have been made. The structures investigated include periodic wedge-type and pyramid-type iron-epoxy calibration loads and flat carbon-foam 'Echosorb' samples. Measurements were made using an HP 8510 network analyzer interfaced with a focused-lens scattering range. The test set provided a dynamic range of approximately 55 dB. Swept frequency measurements over the 75-100-GHz band have revealed specular and Bragg reflection characteristics in the measured data.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126113155","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}
One of the key technologies to be validated as part of the ACTS program is the multibeam antenna with rapidly reconfigurable hopping and fixed spot beam to serve users equipped with small-aperture terminals within the coverage areas. The proposed antenna technology experiments are designed to evaluate in-orbit ACTS multibeam antenna performance (radiation pattern, gain, cross pol levels, etc.). Attention is given here to in-orbit RF antenna pattern measurements, reflector surface temperature measurements, C/N power ratio measurements, and thermal distortion analysis.<>
{"title":"Advanced Communication Technology Satellite (ACTS) multibeam antenna technology verification experiments","authors":"Roberto J. Acosta, J. Larko, A. Lagin","doi":"10.1109/APS.1992.221561","DOIUrl":"https://doi.org/10.1109/APS.1992.221561","url":null,"abstract":"One of the key technologies to be validated as part of the ACTS program is the multibeam antenna with rapidly reconfigurable hopping and fixed spot beam to serve users equipped with small-aperture terminals within the coverage areas. The proposed antenna technology experiments are designed to evaluate in-orbit ACTS multibeam antenna performance (radiation pattern, gain, cross pol levels, etc.). Attention is given here to in-orbit RF antenna pattern measurements, reflector surface temperature measurements, C/N power ratio measurements, and thermal distortion analysis.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126195629","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. Bayliss et al. (1982) (BT) have proposed an arbitrary order approximation based upon the Wilcox (1956) spherical wave function far-field expansion, for the case of a circular or spherical boundary with the source located at the center. In the present work, the BT-type representation is generalized to the case of an arbitrary convex boundary, with the curvature explicitly incorporated. Several possible implementations are compared.<>
a . Bayliss等人(1982)(BT)在Wilcox(1956)球面波函数远场展开的基础上，针对源位于中心的圆形或球形边界的情况，提出了任意阶近似。在目前的工作中，bt型表示被推广到任意凸边界的情况下，曲率显式包含。比较了几种可能的实现。
{"title":"Analytic evaluation of the accuracy of several conformable local absorbing boundary conditions","authors":"D. Meade, G. W. Slade, A. Peterson, K. J. Webb","doi":"10.1109/APS.1992.221881","DOIUrl":"https://doi.org/10.1109/APS.1992.221881","url":null,"abstract":"A. Bayliss et al. (1982) (BT) have proposed an arbitrary order approximation based upon the Wilcox (1956) spherical wave function far-field expansion, for the case of a circular or spherical boundary with the source located at the center. In the present work, the BT-type representation is generalized to the case of an arbitrary convex boundary, with the curvature explicitly incorporated. Several possible implementations are compared.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124702702","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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