Relatively recently, the authors of this present paper proposed an entire-domain Sommerfeld-based method for the analysis of thin-wire antennas in lossy layered media [1]. The accompanying computer program is also available [2]. This paper is aimed at presenting a novel, improved form of the method from Ref. [1]. Namely, some recent investigations have resulted in considerable numerical improvements relating to cases when the horizontal wire segments are very close to dielectric interfaces. These improvements of the method enable the analysis of arbitrary wire antennas above and/or in the lossy layered dielectric, without a single limitation relating to the postition and electrical length of horizontal wire segments.
{"title":"Improved method for the analysis of thin-wire antennas in lossy layered media","authors":"D. Durdevic, B. Popovic","doi":"10.1109/AEM.1996.872846","DOIUrl":"https://doi.org/10.1109/AEM.1996.872846","url":null,"abstract":"Relatively recently, the authors of this present paper proposed an entire-domain Sommerfeld-based method for the analysis of thin-wire antennas in lossy layered media [1]. The accompanying computer program is also available [2]. This paper is aimed at presenting a novel, improved form of the method from Ref. [1]. Namely, some recent investigations have resulted in considerable numerical improvements relating to cases when the horizontal wire segments are very close to dielectric interfaces. These improvements of the method enable the analysis of arbitrary wire antennas above and/or in the lossy layered dielectric, without a single limitation relating to the postition and electrical length of horizontal wire segments.","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115956218","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 characteristics of the antenna to be used on the mobile terminals are an important issue in wireless coinmunications. The aim of such a design is primarily to achieve zero reflection coet’ficient at the frequency of operation. However, the existence of dielectric scatterers i n the vicinity of the antenna, in a real indoor environment (including the presence of the user himself), affect the operation characteristics of it (input impedance, radiation pattern, antenna gain). In addition, multipath fading phenomena are observed.
{"title":"Behaviour of mobile antennas in indoor environment","authors":"C. Capsalis, F. E. Vellis, G. Dimitrakopoulos","doi":"10.1109/AEM.1996.872837","DOIUrl":"https://doi.org/10.1109/AEM.1996.872837","url":null,"abstract":"The characteristics of the antenna to be used on the mobile terminals are an important issue in wireless coinmunications. The aim of such a design is primarily to achieve zero reflection coet’ficient at the frequency of operation. However, the existence of dielectric scatterers i n the vicinity of the antenna, in a real indoor environment (including the presence of the user himself), affect the operation characteristics of it (input impedance, radiation pattern, antenna gain). In addition, multipath fading phenomena are observed.","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"302 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116331927","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}
Since Sommerfeld published his work [1] on the field of a vertical current element located on the surface of lossy half-space (in 1909), radiation from sources located above lossy half-space has been thoroughly investigated. Exact approaches to this problem lead to the solutions given by semi-infinite integrals of Bessel's functions (e.g., Sommerfeld integrals). Their numerical evaluation requires use of special integration techniques and it's time-consuming. Approximate approaches have also been proposed, valid for a limited range of half-space electrical parameters, a limited domain above soil or a limited range of frequencies. All of the exact and approximate methods dealing with the problem (except reflection-coefficient method) start either from the Sommerfeld solution or from its basic idea (the representation of the actual field by means of planewaves). This paper presents a new approximate method, not linked to the Sommerfeld approach or to the known methods of images. The method is conceptually simple, but it enables very accurate and efficient evaluation of the current distribution along, and the impedance of, arbitrary wire antennas.
{"title":"Analysis of arbitrary wire antennas above lossy half-space: new efficient image method","authors":"V. Petrovic, B. Popovic","doi":"10.1109/AEM.1996.872847","DOIUrl":"https://doi.org/10.1109/AEM.1996.872847","url":null,"abstract":"Since Sommerfeld published his work [1] on the field of a vertical current element located on the surface of lossy half-space (in 1909), radiation from sources located above lossy half-space has been thoroughly investigated. Exact approaches to this problem lead to the solutions given by semi-infinite integrals of Bessel's functions (e.g., Sommerfeld integrals). Their numerical evaluation requires use of special integration techniques and it's time-consuming. Approximate approaches have also been proposed, valid for a limited range of half-space electrical parameters, a limited domain above soil or a limited range of frequencies. All of the exact and approximate methods dealing with the problem (except reflection-coefficient method) start either from the Sommerfeld solution or from its basic idea (the representation of the actual field by means of planewaves). This paper presents a new approximate method, not linked to the Sommerfeld approach or to the known methods of images. The method is conceptually simple, but it enables very accurate and efficient evaluation of the current distribution along, and the impedance of, arbitrary wire antennas.","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117229455","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":"Microwave propagation prediction on oversea path under lower troposphere ducting conditions","authors":"I. Sirkova","doi":"10.1109/AEM.1996.872853","DOIUrl":"https://doi.org/10.1109/AEM.1996.872853","url":null,"abstract":"","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114160162","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":"Influence of spontaneous fluctuations of the carriers and photons on the dynamics of pulse-modulated nearly-single-mode injection laser","authors":"Y. Morozov","doi":"10.1109/AEM.1996.873166","DOIUrl":"https://doi.org/10.1109/AEM.1996.873166","url":null,"abstract":"","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116163003","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 system of Maxwell-Bloch type equations, describing cascade stimulate Raman scattering (CSRS) is investigated. We introduce new variables S/sub 3/ and S/sub /I.chemo// which are bilinear in electromagnetic fields and prove, that the corresponding equations possess Lax representation. This fact is used to apply the inverse scattering transform method and to obtain new soliton solutions, for the CSRS. Results are presented for rotational CSRS in H/sub 2/ gas pumped by the second harmonic of Nd : YAG laser. It is expected that our results can be applied to related phenomena such as stimulated Brillouin scattering and beat-wave generation in intense plasma waves.
{"title":"Inverse scattering transform analysis of cascade stimulate raman scattering","authors":"N. Kostov","doi":"10.1109/AEM.1996.873164","DOIUrl":"https://doi.org/10.1109/AEM.1996.873164","url":null,"abstract":"A system of Maxwell-Bloch type equations, describing cascade stimulate Raman scattering (CSRS) is investigated. We introduce new variables S/sub 3/ and S/sub /I.chemo// which are bilinear in electromagnetic fields and prove, that the corresponding equations possess Lax representation. This fact is used to apply the inverse scattering transform method and to obtain new soliton solutions, for the CSRS. Results are presented for rotational CSRS in H/sub 2/ gas pumped by the second harmonic of Nd : YAG laser. It is expected that our results can be applied to related phenomena such as stimulated Brillouin scattering and beat-wave generation in intense plasma waves.","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116208388","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}
Feedforward linearization is an effective technique for improving the linearity of power amplifiers [1][2] especially at microwave frequencies where the output power of currently available devices is limited. Feedforward systems have been designed to improve, microwave power amplifiers' linearity across the 5.9-6.4 GHz and 7.9-8.4 GHz satellite bands. An optimization method was developed to permit a linear design approach and the practical set up of the experimental feedforward systems [3]. Measured results demonstrated at least 20 dB suppression of the intermodulation distortion across the full operating bands employing auxiliary amplifiers with power rating lower than that of the main amplifier. Comparison of the systems developed with the experimental classical feedforward circuit, which employs two amplifiers with the same power rating, demonstrates that more efficient configurations can be adopted without compromising the performance.
{"title":"Experimental microwave feedforward linearized amplifiers","authors":"K. Konstantinou, D. K. Paul","doi":"10.1109/AEM.1996.873137","DOIUrl":"https://doi.org/10.1109/AEM.1996.873137","url":null,"abstract":"Feedforward linearization is an effective technique for improving the linearity of power amplifiers [1][2] especially at microwave frequencies where the output power of currently available devices is limited. Feedforward systems have been designed to improve, microwave power amplifiers' linearity across the 5.9-6.4 GHz and 7.9-8.4 GHz satellite bands. An optimization method was developed to permit a linear design approach and the practical set up of the experimental feedforward systems [3]. Measured results demonstrated at least 20 dB suppression of the intermodulation distortion across the full operating bands employing auxiliary amplifiers with power rating lower than that of the main amplifier. Comparison of the systems developed with the experimental classical feedforward circuit, which employs two amplifiers with the same power rating, demonstrates that more efficient configurations can be adopted without compromising the performance.","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114668517","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":"Electromagnetic wave scattering by time-varying and moving structures","authors":"M. Bakunov, N. S. Stepanov","doi":"10.1109/AEM.1996.873088","DOIUrl":"https://doi.org/10.1109/AEM.1996.873088","url":null,"abstract":"","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114751748","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 spectral, angular, polarizing, air and water temperatures, wave and wind features of a sea surface radar cross section and brightness temperature correlative characteristics are considered. Microwave radar-radianeter correlative method for detection and identification of observed surfaces anomalous fonrations are developed. canbined in space and in time microwave radar-radiometer system for observed surfaces anomalous formations detection and classification, with taking into account of microwave active and passive charmels signals correlative features, are described.
{"title":"Radar-radiometer correlative system","authors":"A. K. Arakelian","doi":"10.1109/AEM.1996.873183","DOIUrl":"https://doi.org/10.1109/AEM.1996.873183","url":null,"abstract":"The spectral, angular, polarizing, air and water temperatures, wave and wind features of a sea surface radar cross section and brightness temperature correlative characteristics are considered. Microwave radar-radianeter correlative method for detection and identification of observed surfaces anomalous fonrations are developed. canbined in space and in time microwave radar-radiometer system for observed surfaces anomalous formations detection and classification, with taking into account of microwave active and passive charmels signals correlative features, are described.","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126113934","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 orthogonal method for geometry synthesis of a linear antenna array is presented. We start from an initial array, and we perturb the element positions by using an iterative procedure and applying the orthogonal method. Applications for arrays with uniform excitation give patterns with the desired sidelobe level.
{"title":"The orthogonal method for the geometry synthesis of a linear antenna array","authors":"G. Miaris, E. Vafiadis, J.N. Sabolos","doi":"10.1109/AEM.1996.872861","DOIUrl":"https://doi.org/10.1109/AEM.1996.872861","url":null,"abstract":"The orthogonal method for geometry synthesis of a linear antenna array is presented. We start from an initial array, and we perturb the element positions by using an iterative procedure and applying the orthogonal method. Applications for arrays with uniform excitation give patterns with the desired sidelobe level.","PeriodicalId":445510,"journal":{"name":"Trans Black Sea Region Symposium on Applied Electromagnetism","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125161578","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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