Pub Date : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637379
G. Fikioris, N. Tsitsas, I. Psarros
The auxiliary surface current, determined by applying the Method of Auxiliary Sources (MAS) to scattering problems by perfect conductors, may exhibit a certain form of oscillations, which are inherent to MAS and are independent of the word-length and the numerical-integration routines. The purpose of the present work is to demonstrate analytically that the “extended integral equation” (which is similar to the MAS one with the main difference that the unknown is the actual surface current on the scatterer) does not exhibit oscillations of the type described above. Hence, oscillations occurring in the extended integral equation are likely to be due to finite word-length or numerical integration errors.
{"title":"Differences between extended-integral-equation and method-of-auxiliary-sources solutions of a simple scattering problem","authors":"G. Fikioris, N. Tsitsas, I. Psarros","doi":"10.1109/URSI-EMTS.2010.5637379","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637379","url":null,"abstract":"The auxiliary surface current, determined by applying the Method of Auxiliary Sources (MAS) to scattering problems by perfect conductors, may exhibit a certain form of oscillations, which are inherent to MAS and are independent of the word-length and the numerical-integration routines. The purpose of the present work is to demonstrate analytically that the “extended integral equation” (which is similar to the MAS one with the main difference that the unknown is the actual surface current on the scatterer) does not exhibit oscillations of the type described above. Hence, oscillations occurring in the extended integral equation are likely to be due to finite word-length or numerical integration errors.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126027250","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637392
T. Warburton
A low storage curvilinear discontinuous Galerkin method for simulating time domain electromagnetic wave propagation is presented. The algorithm has substantially lower storage requirements than the standard discontinuous Galerkin time-domain method when applied to meshes with a large number of curvilinear elements. An analytical energy stability analysis is summarized and some experimental results show that the novel method does not strongly impact accuracy.
{"title":"A low storage curvilinear discontinuous Galerkin time-domain method for electromagnetics","authors":"T. Warburton","doi":"10.1109/URSI-EMTS.2010.5637392","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637392","url":null,"abstract":"A low storage curvilinear discontinuous Galerkin method for simulating time domain electromagnetic wave propagation is presented. The algorithm has substantially lower storage requirements than the standard discontinuous Galerkin time-domain method when applied to meshes with a large number of curvilinear elements. An analytical energy stability analysis is summarized and some experimental results show that the novel method does not strongly impact accuracy.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124496150","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637171
T. Pochiraju, O. Malyuskin, V. Fusco
In this paper we study sub-wavelength imaging by a new type of probe comprising a single cross polarized slot cut into a metal plate which has a wire inserted along its length. Using this arrangement we show by numerical simulation and experimentally that the transmitted near field can be enhanced up to 25dB with respect to the unloaded slot transmission. Moreover, superior near field squeezing results in 0.14 λ FWHM at 0.1λ distance from the slot. The arrangement yields image resolution capability of better than λ/4 at distance between 0.1λ and 0.2λ from the slot.
{"title":"Sub-wavelength near field imaging using a cross polarised slot with wire insert","authors":"T. Pochiraju, O. Malyuskin, V. Fusco","doi":"10.1109/URSI-EMTS.2010.5637171","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637171","url":null,"abstract":"In this paper we study sub-wavelength imaging by a new type of probe comprising a single cross polarized slot cut into a metal plate which has a wire inserted along its length. Using this arrangement we show by numerical simulation and experimentally that the transmitted near field can be enhanced up to 25dB with respect to the unloaded slot transmission. Moreover, superior near field squeezing results in 0.14 λ FWHM at 0.1λ distance from the slot. The arrangement yields image resolution capability of better than λ/4 at distance between 0.1λ and 0.2λ from the slot.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124988984","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637026
Yiwei He, Y. Akizuki
In this paper, the planar spiral antennas for the ground penetrating radar (GPR) were calculated by using FDTD method. The frequency characteristics of the impedance ware discussed by changing the expansion angle of the planar element and the winding angle of the spiral. It was observed that a wide-band characteristics can be realized by a careful design of the antenna shape. Because the transient response of a GPR antenna is very important, the transient radiated electromagnetic wave was also investigated.
{"title":"FDTD analysis of a planar spiral antennas for the ground penetrating radar","authors":"Yiwei He, Y. Akizuki","doi":"10.1109/URSI-EMTS.2010.5637026","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637026","url":null,"abstract":"In this paper, the planar spiral antennas for the ground penetrating radar (GPR) were calculated by using FDTD method. The frequency characteristics of the impedance ware discussed by changing the expansion angle of the planar element and the winding angle of the spiral. It was observed that a wide-band characteristics can be realized by a careful design of the antenna shape. Because the transient response of a GPR antenna is very important, the transient radiated electromagnetic wave was also investigated.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130568431","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637254
L. Klinkenbusch
A spherical-multipole based approach is introduced to efficiently obtain the time-domain near- and far-field of any arbitrary localized current or equivalent-current source distribution. The method is based on the Fourier transform of the frequency-domain spherical-multipole expansion and on a finite expansion of the spherical Hankel function of the 2nd kind. It leads to a time-domain spherical-multipole expansion valid in the free space outside a minimum sphere containing all electromagnetic sources. By means of new recurrence relations the additional time-domain multipole amplitudes needed for the complete representation of the near field can be very efficiently calculated from the time-domain amplitudes dominant in the far field. The latter can be obtained by a recently proposed spherical-multipole based time-domain near-field to far-field algorithm which is particularly suited for FDTD.
{"title":"Spherical-multipole based time-domain near-field to near-field transformation","authors":"L. Klinkenbusch","doi":"10.1109/URSI-EMTS.2010.5637254","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637254","url":null,"abstract":"A spherical-multipole based approach is introduced to efficiently obtain the time-domain near- and far-field of any arbitrary localized current or equivalent-current source distribution. The method is based on the Fourier transform of the frequency-domain spherical-multipole expansion and on a finite expansion of the spherical Hankel function of the 2nd kind. It leads to a time-domain spherical-multipole expansion valid in the free space outside a minimum sphere containing all electromagnetic sources. By means of new recurrence relations the additional time-domain multipole amplitudes needed for the complete representation of the near field can be very efficiently calculated from the time-domain amplitudes dominant in the far field. The latter can be obtained by a recently proposed spherical-multipole based time-domain near-field to far-field algorithm which is particularly suited for FDTD.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128914630","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637311
G. Carluccio, M. Albani
The possibility of reducing the sampling point density in the numerical evaluation of radiation integrals is discussed by resorting to asymptotic high-frequency technique concepts. It is shown that the numerical evaluation of the radiation integrals becomes computationally more efficient by introducing an adaptive sampling. By this approach the number of sampling points results drastically smaller than the standard Nyquist sampling rate.
{"title":"On the use of high-frequency asymptotic concepts for the development of efficient adaptive numerical integration algorithms","authors":"G. Carluccio, M. Albani","doi":"10.1109/URSI-EMTS.2010.5637311","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637311","url":null,"abstract":"The possibility of reducing the sampling point density in the numerical evaluation of radiation integrals is discussed by resorting to asymptotic high-frequency technique concepts. It is shown that the numerical evaluation of the radiation integrals becomes computationally more efficient by introducing an adaptive sampling. By this approach the number of sampling points results drastically smaller than the standard Nyquist sampling rate.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125615604","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637167
Zhongkun Ma, V. Volski, G. Vandenbosch
An innovative 4 element array topology of microstrip E shaped patches for use in WLAN applications is revisited and optimized by a novel Particle Swarm Optimization (PSO) implementation. This optimiser is capable to operate with a reduced number of cost function evaluations, since all evaluated antenna configurations and corresponding cost function values are saved. During the PSO optimization process, the fitness of the particle is evaluated by a full wave solver based on the moment of method. The used cost functions are constructed using s-parameters and the array gain in order to achieve the optimal performance. The operating frequency range is from 3.4 to 3.8 GHz and the gain of the array is more than 13 dB. The main beam direction is normal to the ground plane. Finally CST EM Studio is used to validate the global best antenna candidate structure.
通过新的粒子群优化(PSO)实现，重新审视和优化了用于WLAN应用的微带E形贴片的创新4元素阵列拓扑。该优化器能够减少成本函数评估的数量，因为所有评估的天线配置和相应的成本函数值都被保存。在粒子群优化过程中，采用基于矩量法的全波求解器对粒子的适应度进行评估。为了达到最优的性能，使用s参数和数组增益来构造所使用的代价函数。工作频率范围为3.4 ~ 3.8 GHz，阵列增益大于13db。主波束方向垂直于地平面。最后利用CST EM Studio对全局最佳候选天线结构进行验证。
{"title":"Optimized design of a compact low-cost 4 element microstrip antenna array for WLAN","authors":"Zhongkun Ma, V. Volski, G. Vandenbosch","doi":"10.1109/URSI-EMTS.2010.5637167","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637167","url":null,"abstract":"An innovative 4 element array topology of microstrip E shaped patches for use in WLAN applications is revisited and optimized by a novel Particle Swarm Optimization (PSO) implementation. This optimiser is capable to operate with a reduced number of cost function evaluations, since all evaluated antenna configurations and corresponding cost function values are saved. During the PSO optimization process, the fitness of the particle is evaluated by a full wave solver based on the moment of method. The used cost functions are constructed using s-parameters and the array gain in order to achieve the optimal performance. The operating frequency range is from 3.4 to 3.8 GHz and the gain of the array is more than 13 dB. The main beam direction is normal to the ground plane. Finally CST EM Studio is used to validate the global best antenna candidate structure.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"192 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116521754","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637219
L. Gurel, T. Malas, O. Ergul
The multilevel fast multipole algorithm (MLFMA) is a powerful method that enables iterative solutions of electromagnetics problems with low complexity. Iterative solvers, however, are not robust for three-dimensional complex real-life problems unless suitable preconditioners are used. In this paper, we present our efforts to devise effective preconditioners for MLFMA solutions of difficult electromagnetics problems involving both conductors and dielectrics.
{"title":"Preconditioning iterative MLFMA solutions of integral equations","authors":"L. Gurel, T. Malas, O. Ergul","doi":"10.1109/URSI-EMTS.2010.5637219","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637219","url":null,"abstract":"The multilevel fast multipole algorithm (MLFMA) is a powerful method that enables iterative solutions of electromagnetics problems with low complexity. Iterative solvers, however, are not robust for three-dimensional complex real-life problems unless suitable preconditioners are used. In this paper, we present our efforts to devise effective preconditioners for MLFMA solutions of difficult electromagnetics problems involving both conductors and dielectrics.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125495135","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5636993
M. Stallein, B. Bandlow, R. Schuhmann
Integrated optical waveguides on PCB level are a promising technology to enhance data transfer rates. For minimal tolerance requirements these waveguides are multimodal, accordingly ray optical methods are used to analyze the transfer behavior. In this context the limits of ray optical methods are not well-known. It is the aim of this work to validate these methods by comparison with a wave analysis of bent dielectric slab waveguides. This analysis uses quasi-guided modes that are appropriate to simulate the optical power flow after passing a 90° bend. The fields of a Gaussian beam serve as reference source.
{"title":"Validation of ray optics capability to analyze the transfer behavior of bent optical slab waveguides","authors":"M. Stallein, B. Bandlow, R. Schuhmann","doi":"10.1109/URSI-EMTS.2010.5636993","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5636993","url":null,"abstract":"Integrated optical waveguides on PCB level are a promising technology to enhance data transfer rates. For minimal tolerance requirements these waveguides are multimodal, accordingly ray optical methods are used to analyze the transfer behavior. In this context the limits of ray optical methods are not well-known. It is the aim of this work to validate these methods by comparison with a wave analysis of bent dielectric slab waveguides. This analysis uses quasi-guided modes that are appropriate to simulate the optical power flow after passing a 90° bend. The fields of a Gaussian beam serve as reference source.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126739137","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 : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637361
O. Klemp
Vehicle-to-vehicle (V2V) communications systems focus on the improvement of driver safety and traffic efficiency using the recently designated frequency bands in the 5.9GHz range in Europe. Due to the time-frequency selective fading behaviour of the vehicular communication channel, antenna-related effects impacted by the vehicular mounting position and mutual coupling play an integral role in the performance of V2V communications. This paper focuses on the analysis of characteristic antenna effects that are subject to vehicular mounting. Example multi-element antenna (MEA) topologies are considered to improve the reliability of the wireless link by diversity combining in order to meet the stringent requirements of real-time communications.
{"title":"Performance considerations for automotive antenna equipment in vehicle-to-vehicle communications","authors":"O. Klemp","doi":"10.1109/URSI-EMTS.2010.5637361","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637361","url":null,"abstract":"Vehicle-to-vehicle (V2V) communications systems focus on the improvement of driver safety and traffic efficiency using the recently designated frequency bands in the 5.9GHz range in Europe. Due to the time-frequency selective fading behaviour of the vehicular communication channel, antenna-related effects impacted by the vehicular mounting position and mutual coupling play an integral role in the performance of V2V communications. This paper focuses on the analysis of characteristic antenna effects that are subject to vehicular mounting. Example multi-element antenna (MEA) topologies are considered to improve the reliability of the wireless link by diversity combining in order to meet the stringent requirements of real-time communications.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"10 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120857229","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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