{"title":"HF broadcast transmitting antennas","authors":"A. Paul","doi":"10.1109/APS.1988.94344","DOIUrl":"https://doi.org/10.1109/APS.1988.94344","url":null,"abstract":"An overview is presented of high-frequency (HF) broadcast transmitting antennas. For long-range broadcasting, high-power wideband directive antennas with slewing and beam shaping capabilities are needed. The design requirements, state-of-the-art, and the future trend of these antennas are discussed. Also discussed are the power-handling capability of the antenna, its mechanical requirements, and siting conditions. Currently available HF broadcast antennas are examined. It is shown that beam slewing in discrete steps can be achieved by phase adjustments between antenna elements and between antenna stacks. Continuous beam slewing in the horizontal direction is achievable, in principle, by the phased-array approach.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114679071","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}
{"title":"Propagation characteristics of a corrugated dielectric lined circular waveguide feed","authors":"P. Mccormack, T. Rao","doi":"10.1109/APS.1988.94137","DOIUrl":"https://doi.org/10.1109/APS.1988.94137","url":null,"abstract":"The propagation characteristics of a corrugated-dielectric-lined circular waveguide are analyzed, treating the lining as an anisotropic medium with tensor permittivity. From the preliminary results obtained, the physical parameters and the dielectric constant of the corrugated dielectric lining can be varied to create a desired model of propagation with a reasonable bandwidth. As a result, corrugated dielectric lined circular waveguides could find applications in the design of antenna feeds with high efficiency.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125233515","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}
{"title":"Dielectric-covered waveguide longitudinal slots","authors":"P. Katehi","doi":"10.1109/APS.1988.94320","DOIUrl":"https://doi.org/10.1109/APS.1988.94320","url":null,"abstract":"The presence of a dielectric substrate can alter the characteristics of the individual slots and considerably affect the mutual coupling. To analyze or design such an array, a procedure that includes the above effects is presented. It is based on work by R.S. Elliott et al. (1984) on the analysis and design of similar arrays without the dielectric cover. The authors show how the method is used to study the effect of the cover on the slots' resonant length, resonant admittance, and mutual coupling.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127290867","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}
{"title":"Conditions for coalescence of the full wave solutions for rough surface EM scattering with perturbation and physical optics solutions in the low and high frequency limits-theory and experiment","authors":"E. Bahar","doi":"10.1109/APS.1988.94191","DOIUrl":"https://doi.org/10.1109/APS.1988.94191","url":null,"abstract":"A full wave solution based on the complete expansion of the fields and the imposition of exact boundary conditions was developed to investigate propagation in irregular stratified media. On applying this approach to scattering and depolarization by two dimensionally rough surfaces separating two media with arbitrary (complex) permittivity and permeability, it was shown that closed-form expressions for the surface element scattering coefficients depend on the polarizations and directions of the incident and scattered waves, the relative complex permittivity and permeability of the media, and the direction of the normal to the two-dimensionally rough surface. It was also shown that the full-wave results satisfied the duality, reciprocity, and realizability relationships in electromagnetic theory and that they were invariant to coordinate transformations.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125005969","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}
{"title":"Full wave space domain solution for microstrip lines","authors":"N. Faché, D. De Zutter","doi":"10.1109/APS.1988.94263","DOIUrl":"https://doi.org/10.1109/APS.1988.94263","url":null,"abstract":"A full-wave solution is proposed in the space domain starting from the calculation of a Green's dyadic function in the spectral domain. The surface current is discretized using the method of moments in such a way that the edge conditions are satisfied. The boundary conditions on the strip are not imposed in some global sense as in the spectral domain technique, but at a number of points spaced along the strip. As the treatment does not start from a closed-form expression of the current of the strip, it is possible to examine the influence of the frequency on the current distribution. Special attention is devoted to the calculation of the characteristic impedance.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123029194","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}
{"title":"The methodology of boundary methods","authors":"W. Zhang","doi":"10.1109/APS.1988.94054","DOIUrl":"https://doi.org/10.1109/APS.1988.94054","url":null,"abstract":"Boundary methods are briefly discussed with respect to frequency-domain methods for electromagnetic problem solving. A framework connecting various individually developed boundary methods under a simply unifying 'umbrella' is given. Exclusions to the boundary element method (BEM) are briefly highlighted.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114405875","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}
{"title":"Grating lobe pattern mapping over pitch and roll of a triangular lattice planar array","authors":"R. Cock","doi":"10.1109/APS.1988.94307","DOIUrl":"https://doi.org/10.1109/APS.1988.94307","url":null,"abstract":"A method is presented to determine the maximum lattice spacing of a triangular lattice array that will maintain a clear specified scan area (clear from spurious grating lobe beams) as the antenna proceeds through a specified pitch and roll. A uniformly spaced lattice of isotropic radiators is assumed.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129766774","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}
{"title":"Reflections in open-ended elliptical waveguide with an infinite flange","authors":"T. Bird","doi":"10.1109/APS.1988.94318","DOIUrl":"https://doi.org/10.1109/APS.1988.94318","url":null,"abstract":"Experience with smooth-wall horn radiators of rectangular and circular cross-section has shown that significant reflection can occur from apertures of moderate size, resulting in mismatch at the horn input. The existing literature gives no indication of the level of reflection in open-ended elliptical waveguide, although W.C. Chew et al. (1986) recently formulated the problem. The purpose of this study is to outline another solution to the problem and to present preliminary theoretical results. To demonstrate the effect of the open end, the computed reflection coefficient of the TE/sub c11/ mode is plotted as a function of normalized frequency ka with waveguide ellipticity as a parameter. In these calculations, coupling to other modes in the aperture was neglected, an approximation known to work well provided the high-order modes are below cutoff. Reflection in elliptical waveguides increases as a/b increases in much the same way as reflection of the TE/sub 10/ mode in rectangular waveguides. Well above cutoff, the level of reflection of the TE/sub c11/ mode was found to be approximately the same as for the TE/sub 10/ mode in open-ended rectangular waveguides with the same value of a/b.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128716611","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}
{"title":"Mutual impedance between microstrip patch antennas","authors":"A. Mohammadian, N. Martin, D. Griffin","doi":"10.1109/APS.1988.94240","DOIUrl":"https://doi.org/10.1109/APS.1988.94240","url":null,"abstract":"An approximate model for the patch element, based on cavity model expansion, is adopted. The model has been improved by taking into account the effect of the substrate by constructing a dyadic Green's function for the grounded dielectric substrate utilizing the rectangular vector wave functions (RVWF). The reaction concept has been used to evaluate the mutual impedance between the patches. The integrations over the source region to evaluate the H-fields as well as those in the mutual impedance formula have been performed analytically. The remaining integrations which are in spectral domain have been evaluated numerically by using the fast Fourier transform (FFT). It was found that the method can be used to evaluate the mutual impedance between microstrip patch antennas with great accuracy for typical substrate thicknesses in L- and C-bands. The agreement between the calculated results and measurements have been found to be excellent. It is expected that the method will also work reasonably well in higher frequency bands.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129261459","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}
{"title":"Analysis of the tapered slotline antenna on a dielectric substrate","authors":"S. Zhong, H. Zhang","doi":"10.1109/APS.1988.94303","DOIUrl":"https://doi.org/10.1109/APS.1988.94303","url":null,"abstract":"An analysis of the tapered slot antenna has been developed using the Galerkin method in the Fourier domain and aperture integration using Green's function. Comparison between theory and experiment shows very good agreement. The method enables the authors to analyze tapered slotline antennas with different slotline profiles and parameters and to facilitate successful designs.<<ETX>>","PeriodicalId":211271,"journal":{"name":"1988 IEEE AP-S. International Symposium, Antennas and Propagation","volume":" 39","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120826987","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}