Pub Date : 1900-01-01DOI: 10.1109/IRETAP.1956.6366294
E. Jones, T. Morita, S. B. Cohnf
Two microwave lenses whose surfaces have been matched respectively by embedded capacitive walls and by simulated quarter-wave transformers were built and compared experimentally to an unmatched lens of identical aperture and focal length. At the design frequency, the matched lenses exhibited reductions in side-lobe level of 14 and 10 db with respect to the unmatched lens, and increases in over-all gain of 0.35 and 0.1 db. The input vswr of the feed horn was reduced from 1.6 for the unmatched case to 1.02 and 1.05 for the matched cases. The bandwidth of good performance for the two lenses ranged from lö per cent to at least 44 per cent
{"title":"Measured performance of matched dielectric lenses","authors":"E. Jones, T. Morita, S. B. Cohnf","doi":"10.1109/IRETAP.1956.6366294","DOIUrl":"https://doi.org/10.1109/IRETAP.1956.6366294","url":null,"abstract":"Two microwave lenses whose surfaces have been matched respectively by embedded capacitive walls and by simulated quarter-wave transformers were built and compared experimentally to an unmatched lens of identical aperture and focal length. At the design frequency, the matched lenses exhibited reductions in side-lobe level of 14 and 10 db with respect to the unmatched lens, and increases in over-all gain of 0.35 and 0.1 db. The input vswr of the feed horn was reduced from 1.6 for the unmatched case to 1.02 and 1.05 for the matched cases. The bandwidth of good performance for the two lenses ranged from lö per cent to at least 44 per cent","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114958187","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 : 1900-01-01DOI: 10.1109/TAP.1962.1137807
H. Raemer
{"title":"Radiation from linear electric or magnetic antennas surrounded by a spherical plasma shell","authors":"H. Raemer","doi":"10.1109/TAP.1962.1137807","DOIUrl":"https://doi.org/10.1109/TAP.1962.1137807","url":null,"abstract":"","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129588920","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 : 1900-01-01DOI: 10.1109/IRETAP.1956.6366298
P. N. Mathur, E. Mueller
Studies were made of the scattering of electromagnetic waves from nonspherical targets by making exact determination of the nose-on radar back-scattering cross sections of conducting prolate spheroids of various sizes and shapes. Curves are given for the back-scattered cross sections as a function of dimensionless size and shape parameters for prolate spheroids. The results are compared with the Rayleigh-Gans first order approximation and Stevenson's third-order approximation, and the range of applicability of these approximations is evaluated.
{"title":"Radar back-scattering cross sections for nonspherical targets","authors":"P. N. Mathur, E. Mueller","doi":"10.1109/IRETAP.1956.6366298","DOIUrl":"https://doi.org/10.1109/IRETAP.1956.6366298","url":null,"abstract":"Studies were made of the scattering of electromagnetic waves from nonspherical targets by making exact determination of the nose-on radar back-scattering cross sections of conducting prolate spheroids of various sizes and shapes. Curves are given for the back-scattered cross sections as a function of dimensionless size and shape parameters for prolate spheroids. The results are compared with the Rayleigh-Gans first order approximation and Stevenson's third-order approximation, and the range of applicability of these approximations is evaluated.","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"181 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132016233","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 : 1900-01-01DOI: 10.1109/TAP.1957.1144483
G. Marconi
{"title":"Radio communications by means of very short electric waves","authors":"G. Marconi","doi":"10.1109/TAP.1957.1144483","DOIUrl":"https://doi.org/10.1109/TAP.1957.1144483","url":null,"abstract":"","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122919584","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 : 1900-01-01DOI: 10.1109/IRETAP.1956.6366291
L. Felsen
The pattern in a half-space of a slot in the wall of a waveguide is a function of the terminating impedance. The description of the far fields in such a configuration is simplified considerably by the adoption of a network viewpoint, whereby the half-space is represented approximately by two (or more) spherical transmission lines, the feeding waveguide by a single uniform transmission line, and the slot by a coupling network which is directly analogous to that for a hybrid junction. For a given waveguide termination, the spherical mode voltages are computed by a simple network calculation, and the gain pattern is obtained by modal synthesis. The slot equivalent circuit parameters are obtained readily by simple measurements or from available theoretical formulas. Described in detail both theoretically and experimentally is a symmetric rectangular slot cut in either the broad or narrow face of a rectangular waveguide.
{"title":"Analysis of a terminated-waveguide slot antenna by an equivalent circuit method","authors":"L. Felsen","doi":"10.1109/IRETAP.1956.6366291","DOIUrl":"https://doi.org/10.1109/IRETAP.1956.6366291","url":null,"abstract":"The pattern in a half-space of a slot in the wall of a waveguide is a function of the terminating impedance. The description of the far fields in such a configuration is simplified considerably by the adoption of a network viewpoint, whereby the half-space is represented approximately by two (or more) spherical transmission lines, the feeding waveguide by a single uniform transmission line, and the slot by a coupling network which is directly analogous to that for a hybrid junction. For a given waveguide termination, the spherical mode voltages are computed by a simple network calculation, and the gain pattern is obtained by modal synthesis. The slot equivalent circuit parameters are obtained readily by simple measurements or from available theoretical formulas. Described in detail both theoretically and experimentally is a symmetric rectangular slot cut in either the broad or narrow face of a rectangular waveguide.","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117103570","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 : 1900-01-01DOI: 10.1109/IRETAP.1956.6366297
J. Wait, M. O'Grady
The distribution of surface current density on a perfectly conducting half-plane excited by an infinite axial slot is determined. The slot is assumed to be of small width and it is excited throughout its length by a uniform transverse voltage. It is shown that the surface currents which flow toward the edge of the half-plane are somewhat smaller than they would be if they were on an infinite plane. For sake of comparison the surface currents of an infinite axial slot on a thin elliptic cylinder or ribbon are also examined
{"title":"Surface currents excited by an infinite slot on half-planes and ribbons","authors":"J. Wait, M. O'Grady","doi":"10.1109/IRETAP.1956.6366297","DOIUrl":"https://doi.org/10.1109/IRETAP.1956.6366297","url":null,"abstract":"The distribution of surface current density on a perfectly conducting half-plane excited by an infinite axial slot is determined. The slot is assumed to be of small width and it is excited throughout its length by a uniform transverse voltage. It is shown that the surface currents which flow toward the edge of the half-plane are somewhat smaller than they would be if they were on an infinite plane. For sake of comparison the surface currents of an infinite axial slot on a thin elliptic cylinder or ribbon are also examined","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124047978","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 : 1900-01-01DOI: 10.1109/IRETAP.1956.6366304
R. Kirby, F. Capps
A study has been made of the correlation in transmission loss observed over irregular-terrain paths. Simultaneous mobile measurements were made of two pairs of VHF broadcasting stations in the Washington, D. C-Baltimore, Maryland area. The correlation coefficients derived from sample sets of transmission loss data indicate that when reception is from opposite directions, no significant correlation is evident, and when the paths of propagation are the same even though the frequencies are separated considerably, the correlation appears to be significantly high.
{"title":"Correlation in VHF propagation over irregular terrain","authors":"R. Kirby, F. Capps","doi":"10.1109/IRETAP.1956.6366304","DOIUrl":"https://doi.org/10.1109/IRETAP.1956.6366304","url":null,"abstract":"A study has been made of the correlation in transmission loss observed over irregular-terrain paths. Simultaneous mobile measurements were made of two pairs of VHF broadcasting stations in the Washington, D. C-Baltimore, Maryland area. The correlation coefficients derived from sample sets of transmission loss data indicate that when reception is from opposite directions, no significant correlation is evident, and when the paths of propagation are the same even though the frequencies are separated considerably, the correlation appears to be significantly high.","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"166 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126594706","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 : 1900-01-01DOI: 10.1109/iretap.1956.6366308
A SYMPOSIUM on Normal Mode Theory was convened, under the chairmanship of Dr. S. A. Schelkunoff, at the Navy Electronics Laboratory on July 5, 6, and 7, 1955. This symposium consisted of an informal trip to Palomar Mountain on July 5 and a round-table discussion on July 6-7 for the purpose of exchanging ideas about the present state of theoretical knowledge of wave propagation through stratified media, the known methods of attack, and the outstanding unanswered questions. Although the emphasis was on normal mode theory, the possibility of extending the ray theory of physical optics was explored. The following list of topics was on the agenda:
1955年7月5日、6日和7日，在海军电子实验室召开了一次关于正模理论的研讨会，由S. A. Schelkunoff博士主持。本次研讨会包括7月5日对帕洛玛山的非正式访问和7月6日至7日的圆桌讨论，目的是就波通过分层介质传播的理论知识的现状、已知的攻击方法和悬而未决的问题交换意见。虽然重点是正模理论，但也探讨了扩展物理光学射线理论的可能性。议程上的议题清单如下:
{"title":"Summary of normal mode theory symposium","authors":"","doi":"10.1109/iretap.1956.6366308","DOIUrl":"https://doi.org/10.1109/iretap.1956.6366308","url":null,"abstract":"A SYMPOSIUM on Normal Mode Theory was convened, under the chairmanship of Dr. S. A. Schelkunoff, at the Navy Electronics Laboratory on July 5, 6, and 7, 1955. This symposium consisted of an informal trip to Palomar Mountain on July 5 and a round-table discussion on July 6-7 for the purpose of exchanging ideas about the present state of theoretical knowledge of wave propagation through stratified media, the known methods of attack, and the outstanding unanswered questions. Although the emphasis was on normal mode theory, the possibility of extending the ray theory of physical optics was explored. The following list of topics was on the agenda:","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127327536","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 : 1900-01-01DOI: 10.1109/IRETAP.1956.6366295
T. Morita, S. Cohn
The reflections from the surface of a dielectric lens may be cancelled by a quarter-wavelength layer of refractive index intermediate between that of air and the lens medium. The possibility of simulating a quarter-wave matching section by perturbing the boundary of the lens is described in this paper. Some of the configurations considered are corrugated surfaces, arrays of dielectric cylinders, and arrays of holes in the dielectric surface. In each case, a match may be obtained at a given frequency and angle of incidence by the proper adjustment of the depth of the perturbation, and of one other parameter such as the width of a groove.
{"title":"Microwave lens matching by simulated quarter-wave transformers","authors":"T. Morita, S. Cohn","doi":"10.1109/IRETAP.1956.6366295","DOIUrl":"https://doi.org/10.1109/IRETAP.1956.6366295","url":null,"abstract":"The reflections from the surface of a dielectric lens may be cancelled by a quarter-wavelength layer of refractive index intermediate between that of air and the lens medium. The possibility of simulating a quarter-wave matching section by perturbing the boundary of the lens is described in this paper. Some of the configurations considered are corrugated surfaces, arrays of dielectric cylinders, and arrays of holes in the dielectric surface. In each case, a match may be obtained at a given frequency and angle of incidence by the proper adjustment of the depth of the perturbation, and of one other parameter such as the width of a groove.","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132703288","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 : 1900-01-01DOI: 10.1109/IRETAP.1956.6366300
H. A. Myers
This paper describes the radiation pattern of the un-symmetrically-fed prolate spheroidal transmitting antenna. Maxwell's equations are solved in prolate spheroidal coordinates subject to the boundary conditions. The prolate spheroidal functions are expressed in the form of power series and Laurent series. Radiation patterns have been obtained for antennas of three different lengths up to about one wavelength long, for length/thickness ratios of about 5/1, 10/1,22/1, and 316/1, and for nine unsymmetrical gap locations as well as for the symmetrically-fed cases. It was found that the two most important factors affecting the radiation pattern of a fairly thin antenna were the location of the gap and the electrical length. For antennas less than a half wavelength long, the pattern was the usual symmetrical figure eight and was essentially independent of the location of the gap (except for magnitude changes due to the different gap impedances). For antennas two-thirds to three-quarters of a wavelength long the figure eight patterns could be "bent" in the direction of the longer element, and for antennas one wavelength long or longer minor lobes began to appear.
{"title":"Radiation patterns of unsymmetrically fed prolate spheroidal antennas","authors":"H. A. Myers","doi":"10.1109/IRETAP.1956.6366300","DOIUrl":"https://doi.org/10.1109/IRETAP.1956.6366300","url":null,"abstract":"This paper describes the radiation pattern of the un-symmetrically-fed prolate spheroidal transmitting antenna. Maxwell's equations are solved in prolate spheroidal coordinates subject to the boundary conditions. The prolate spheroidal functions are expressed in the form of power series and Laurent series. Radiation patterns have been obtained for antennas of three different lengths up to about one wavelength long, for length/thickness ratios of about 5/1, 10/1,22/1, and 316/1, and for nine unsymmetrical gap locations as well as for the symmetrically-fed cases. It was found that the two most important factors affecting the radiation pattern of a fairly thin antenna were the location of the gap and the electrical length. For antennas less than a half wavelength long, the pattern was the usual symmetrical figure eight and was essentially independent of the location of the gap (except for magnitude changes due to the different gap impedances). For antennas two-thirds to three-quarters of a wavelength long the figure eight patterns could be \"bent\" in the direction of the longer element, and for antennas one wavelength long or longer minor lobes began to appear.","PeriodicalId":133512,"journal":{"name":"IRE Transactions on Antennas and Propagation","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128938065","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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