2007 IEEE Applied Electromagnetics Conference (AEMC)最新文献

{"title":"A selective review of high-frequency techniques in computational electromagnetics","authors":"Deb Chatterjee","doi":"10.1109/AEMC.2007.4638048","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638048","url":null,"abstract":"Solution to high-frequency electromagnetic problems require increased computational resources if ldquoexactrdquo numerical techniques such as finite difference time domain (FDTD), finite element methods (FEM), or, the method of moments (MoM) with free-space Greenpsilas function, are used. These approaches require discretization of the entire structure into cubic cells of sizes between lambda/10 and lambda/20 , with still finer gridding near source and material interface regions. This process yields accurate results, but consumes computational resources directly proportional to the electrical size of the problem. An alternative to such exact approaches is the access to, and application of, analytical techniques that have the potential to generate better-than-acceptable answers in these high frequency regions. These special class of techniques, developed from the principles of quasi- or ray-optics and their sophisticated extensions, have found extensive applications for a wide variety of problems. Notable amongst a class of ray-optic analysis methods are: uniform theory of diffraction (UTD), physical theory of diffraction (PTD) and the spectral theory of diffraction (STD). A common interesting feature is that the computation time is inversely proportional to the electrical size of the problem and thus serves to complement the exact approaches. Additionally, due to the nature of these quasi- or ray-optic methods, the dominant contributors to the complete solution can be realized in terms of ldquoraysrdquo that provide deeper physical insight into the various electromagnetic interaction mechanisms. In this exposition, the early experimental work on light scattering by perfectly conducting circular cylinders, and mathematical foundations of the state-of-art ray-optic methodologies are comprehensively reviewed. The versatility of the high-frequency, ray-optic techniques will be exemplified through some select numerical examples from the NEC-BSC version 4.2 (numerical electromagnetics code - basic scattering code), that employs the UTD formulations. Recent research topics associated with the present high-frequency methods, such as the Stokes phenomenon, complex rays, hybrid ray-mode methods are discussed, followed by an extensive list of references.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"234 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128942830","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":"Adaptive antenna using Fuzzy Logic Control","authors":"N. Gupta, Ashoka Reddy","doi":"10.1109/AEMC.2007.4638007","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638007","url":null,"abstract":"The present paper deals with a scheme to realize a smart and adaptive antenna for the Mobile base-station using fuzzy logic control. This ldquofuzzy logic based adaptive antenna array systemrdquo determines the required deviation to be brought in for controlling the orientation of the base station antenna beam towards the mobile unit. It can also take care of the varying and uncertain feature inherent to the mobile unit tracking process besides incorporating the effect of the random weight fluctuation.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"17 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113971238","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":"Solving complex wave guide structures using hybrid modes and its application in analysis of a wide reject band waveguide iris filter","authors":"M. Mahani, M. Tayarani","doi":"10.1109/AEMC.2007.4638042","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638042","url":null,"abstract":"An E-plane low-pass waveguide structure is analyzed and its generalized scattering matrix (GSM) derived using the proposed set of hybrid modes in a mode matching technique. The selected mode set shows its superiority over the common TE-TM mode set in faster convergence, simplicity of equations and reducing the order of coupling matrices needed for solving the structure. Comparison of the results with ANSOFT HFSS shows the method is accurate. Finally, the low-pass structures are embedded into a band-pass filter and the response of the whole structure is computed using the same method.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"477 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115323930","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":"Microstrip radiating structures: Theoretical and experimental investigations executed in recent years at the University of Calcutta","authors":"D. Guha, J. Siddiqui, M. Biswas, S. Chattopadhyay, S. Biswas","doi":"10.1109/AEMC.2007.4638062","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638062","url":null,"abstract":"In this paper, we have presented a comprehensive review of research on microstrip antennas conducted at the Institute of radio Physics and Electronics, University of Calcutta with an emphasis to those done in recent years.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126052441","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":"Broadband circularly polarized proximity coupled microstrip antenna for HIPERLAN/2","authors":"Jibendu Sekhar Roy, M. Thomas, Jayanta Ghosh","doi":"10.1109/AEMC.2007.4638000","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638000","url":null,"abstract":"The characteristics of a proximity coupled microstrip antenna, for the application in high performance local area network type 2 (HIPERLAN/2) are reported here. This miniaturized circularly polarized microstrip antenna has wide bandwidth. The simulated results using IE3D software are verified by measurement.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129723553","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":"Simulated resonant characteristics of embedded metamaterial patch antenna","authors":"D. Mishra, G. Arun Kumar, D. R. Poddar, R. K. Mishra","doi":"10.1109/AEMC.2007.4638017","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638017","url":null,"abstract":"This paper presents various observations, from electromagnetic simulations, of a metamaterial embedded patch antenna. The composite right left handed (CRLH) transmission line (TL) metamaterial is the metamaterial under consideration. The schematic structure of the CRLH TL embedded in a patch antenna is shown. This structure is supported on a substrate of thickness 1.59 mm and dielectric constant 2.4. Compared to a simple probe fed patch antenna there is an improvement for the metamaterial embedded patch. Simulations have been done by inserting a single and a double metamaterial structure in the patch antenna. There is an increase in gain, antenna efficiency, shift in resonant frequency and dual frequency of operation for the embedded metamaterial patch.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132535722","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":"CAD of mechanically tunable rectangular microstrip patch with variable aspect ratio","authors":"S. Chattopadhyay, M. Biswas, J. Siddiqui, D. Guha","doi":"10.1109/AEMC.2007.4638016","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638016","url":null,"abstract":"An improved CAD formulation is proposed to determine accurate input impedance of rectangular microstrip patches with variable aspect ratio. This paper demonstrate the effect of aspect ratio of rectangular microstrip patch on its input impedance. The computed results have been verified with our own experiments and simulated data showing very close agreement amongst them.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133832555","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":"Cut-off wave number and dispersion characteristics of eccentric annular guide with dielectric support","authors":"R. Dey, I. Agnihotri, Soumyabrata Chakrabarty, S. Sharma","doi":"10.1109/AEMC.2007.4638043","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638043","url":null,"abstract":"The paper presents a rigorous analysis of a uniform waveguide with circular outer conductor and eccentric inner conductor supported by dielectric slab between the inner and outer conductors. A vector finite element approach in which non-physical spurious solutions do not appear has been followed to study the cut-off frequencies of higher-order modes as well as dispersion characteristics of this guiding structure. Numerical data on cut-off wave numbers and dispersion characteristics have been presented.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124422277","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":"Highly efficient parallel schemes using out-of-core solver for MoM","authors":"Yu Zhang, T. Sarkar, P. Ghosh, M. Taylor, A. De","doi":"10.1109/AEMC.2007.4638049","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638049","url":null,"abstract":"Currently, the problem size that can be solved in reasonable time using the method of moments (MoM) is limited by the amount of memory installed on the computer. This paper offers a new development which not only breaks this memory constraint, but also maintains the efficiency of running the problem in-core. In this paper, highly efficient parallel matrix filling schemes are presented for parallel in-core and parallel out-of-core method of moments (MoM) integral equation solvers with RWG basis functions. The parallel in-core solver uses RAM, which is often expensive and limited in size. The parallel out-of-core solver is introduced to extend the capability of MoM to solve larger problems which can be as large as the amount of storage on the hard disk. Numerical results on several typical computer platforms show that the parallel matrix filling schemes and matrix equation solvers introduced here are highly efficient and achieve theoretical predictions. The implementation of these advancements with the widely used RWG basis function creates a powerful tool for efficient computational electromagnetic solution of complex real world problems.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130008849","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":"Neural network modeling for the fast estimation of superstrate loading effect on rectangular microstrip patch antennas","authors":"S. Chakraborty, S. Mandal, B. Gupta","doi":"10.1109/AEMC.2007.4638015","DOIUrl":"https://doi.org/10.1109/AEMC.2007.4638015","url":null,"abstract":"A neural network model for the shift in resonant frequency of a rectangular microstrip antenna covered with a dielectric layer is presented. The primary effect of such loading is to change the resonant frequency of the antenna. The absolute value of change increases with operating frequency, relative permittivity and the thickness of the dielectric layer. This change may cause degradation in performance due to the inherently narrow bandwidth of microstrip antennas, if the effect of loading is not considered in the design. The neural network model presented here may be used to design microstrip antennas that may be subjected to icing or other atmospheric deposition or coated with protective layers. The model developed is found to be in good agreement with electromagnetic simulation using method of moments.","PeriodicalId":397229,"journal":{"name":"2007 IEEE Applied Electromagnetics Conference (AEMC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131027076","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}