Pub Date : 2010-11-15DOI: 10.1109/URSI-EMTS.2010.5637225
P. Kowalczyk, M. Mrozowski
In this paper an accurate boundary condition is applied for analysis of open waveguiding structures properties. All types of modes are considered: guided, leaky and complex modes. The scheme is based on analytical solution obtained for homogeneous structure. The accuracy of the results is much better than in standard algorithm involving PML technique. The numerical tests show that the improvement is especially noticeable for imaginary part of the propagation coefficient which represents the radiation effects.
{"title":"Highly accurate Finite Difference analysis of leaky, guided and complex waves in photonic optical fibres and dielectric waveguidning structures","authors":"P. Kowalczyk, M. Mrozowski","doi":"10.1109/URSI-EMTS.2010.5637225","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637225","url":null,"abstract":"In this paper an accurate boundary condition is applied for analysis of open waveguiding structures properties. All types of modes are considered: guided, leaky and complex modes. The scheme is based on analytical solution obtained for homogeneous structure. The accuracy of the results is much better than in standard algorithm involving PML technique. The numerical tests show that the improvement is especially noticeable for imaginary part of the propagation coefficient which represents the radiation effects.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"39 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":"128136447","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.2010.5637234
C. Schmidt, T. Laitinen, T. Eibert
Near-field measurement and transformation techniques are widely applied to characterize the radiation pattern of antennas. Spherical near-field measurements have been researched widely and various techniques with different probe compensation capabilities and complexities exist. Among those techniques applicable for (almost) arbitrary probes and based on spherical wave translations, the crucial computational relaxations have been gained through the use of a Fourier Transform based preprocessing of the measurement data. It is shown in this paper that the same Fourier Transform based preprocessing step can be applied in conjunction with the plane wave based probe-corrected near-field far-field transformations. The collection of probe signals is split into smaller sub sets by an Inverse Fast Fourier Transform. These sub problems can be solved with a reduced overall complexity and also a full probe correction is achieved.
{"title":"Fast Fourier Transform preprocessing for accelerated plane wave based spherical near-field far-field transformation","authors":"C. Schmidt, T. Laitinen, T. Eibert","doi":"10.1109/URSI-EMTS.2010.5637234","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637234","url":null,"abstract":"Near-field measurement and transformation techniques are widely applied to characterize the radiation pattern of antennas. Spherical near-field measurements have been researched widely and various techniques with different probe compensation capabilities and complexities exist. Among those techniques applicable for (almost) arbitrary probes and based on spherical wave translations, the crucial computational relaxations have been gained through the use of a Fourier Transform based preprocessing of the measurement data. It is shown in this paper that the same Fourier Transform based preprocessing step can be applied in conjunction with the plane wave based probe-corrected near-field far-field transformations. The collection of probe signals is split into smaller sub sets by an Inverse Fast Fourier Transform. These sub problems can be solved with a reduced overall complexity and also a full probe correction is achieved.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"123 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":"133267886","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.2010.5637313
K. Ito, M. Ando, T. Shijo
PO-MoM is a hybrid method where Physical Optics Current Approximation is corrected by addition of the Fringe wave component (FW) obtained by Method of Moment (MoM). Authors have succeeded to define/localize the areas for the MoM on the scatterer by introducing the Fresnel zone number. Unfortunately, this area extends most of the scatterer surface for some specific combinations of the source and the observer and reduction of computational load fails. This paper introduces another high frequency concept of locality of diffraction, Local-MoM, proposed by the authors, for compensating this defect. Combined use of PO-MoM and Local-MoM realizes almost frequency independent number of unknowns.
{"title":"Combined use of PO-MoM and Local-MoM for reducing MoM areas for wide angular observation points","authors":"K. Ito, M. Ando, T. Shijo","doi":"10.1109/URSI-EMTS.2010.5637313","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637313","url":null,"abstract":"PO-MoM is a hybrid method where Physical Optics Current Approximation is corrected by addition of the Fringe wave component (FW) obtained by Method of Moment (MoM). Authors have succeeded to define/localize the areas for the MoM on the scatterer by introducing the Fresnel zone number. Unfortunately, this area extends most of the scatterer surface for some specific combinations of the source and the observer and reduction of computational load fails. This paper introduces another high frequency concept of locality of diffraction, Local-MoM, proposed by the authors, for compensating this defect. Combined use of PO-MoM and Local-MoM realizes almost frequency independent number of unknowns.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"55 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":"133031756","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.2010.5637083
A. Derneryd, J. Fridén, A. Stjernman
Performance of two 0.3 wavelengths separated antennas in the 700 MHz band are evaluated and improved by connecting a matching and decoupling network to the antenna ports. It is shown through simulations that the network improves efficiency, diversity gain, MIMO Shannon capacity, and reduces the correlation coefficient. The concept is implemented and validated in two dual-antenna mock-ups with slightly different ground plane sizes.
{"title":"MIMO performance of closely spaced antennas in the 700 MHz band","authors":"A. Derneryd, J. Fridén, A. Stjernman","doi":"10.1109/URSI-EMTS.2010.5637083","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637083","url":null,"abstract":"Performance of two 0.3 wavelengths separated antennas in the 700 MHz band are evaluated and improved by connecting a matching and decoupling network to the antenna ports. It is shown through simulations that the network improves efficiency, diversity gain, MIMO Shannon capacity, and reduces the correlation coefficient. The concept is implemented and validated in two dual-antenna mock-ups with slightly different ground plane sizes.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"4 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":"123129917","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.2010.5637219
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.2010.5637174
A. Hirata, K. Sugiura, Y. Kanai, O. Fujiwara
The present study investigates the correlation between maximum temperature elevation and peak mass-averaged specific absorption rates (SARs) in layered one-dimensional model and layered cubical model. The resolution of the model is 0.5 mm or less in order to calculate the correlation in frequencies up to 10 GHz. Our computational investigation in the one-dimensional model showed that the variability due to the thickness is several dozen percents or more, which is dependent on the frequency. In the three-dimensional homogeneous model, SARs averaged over 10 g provides reasonable correlation with maximum temperature elevation for frequencies up to 6 GHz. For the layered cubical model, the SAR averaged over 1g provides better frequency characteristics of the correlation with the maximum temperature elevation, while the variability of the ratio for different tissue thickness remains future work.
{"title":"Correlation between peak spatial-average SAR and maximum temperature elevation in layered cubical model in the frequency range above 3 GHz","authors":"A. Hirata, K. Sugiura, Y. Kanai, O. Fujiwara","doi":"10.1109/URSI-EMTS.2010.5637174","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637174","url":null,"abstract":"The present study investigates the correlation between maximum temperature elevation and peak mass-averaged specific absorption rates (SARs) in layered one-dimensional model and layered cubical model. The resolution of the model is 0.5 mm or less in order to calculate the correlation in frequencies up to 10 GHz. Our computational investigation in the one-dimensional model showed that the variability due to the thickness is several dozen percents or more, which is dependent on the frequency. In the three-dimensional homogeneous model, SARs averaged over 10 g provides reasonable correlation with maximum temperature elevation for frequencies up to 6 GHz. For the layered cubical model, the SAR averaged over 1g provides better frequency characteristics of the correlation with the maximum temperature elevation, while the variability of the ratio for different tissue thickness remains future work.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"134 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":"134084676","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.2010.5637337
L. Reichardt, T. Schipper, T. Zwick
Future mobile communications, in the mean of Car-to-Car (C2C), Car-to-Infrastructure (C2I) or Vehicle-to-Vehicle (V2V) communication, will make use of multiple antenna systems like diversity or MIMO. Especially in multiple antenna systems finding the optimal antenna configuration in order to ensure the best performance is a very difficult task. Presently antennas in mobile communications systems, especially in cars, are selected in a rather expensive and time consuming test-drives, if at all. This will not be technically possible and affordable for multiple antenna systems in the future. Here a solution for this problem is demonstrated defined as Virtual Drive. In the Virtual Drive the quality of the antenna system is determined by simulating the mobile, driving through the EM-fields radiated from the transmitter. The multi-path propagation from the transmitter is calculated by a 3D ray-tracing tool, which is based on the theory of geometrical optics (GO) and the Uniform Theory of Diffraction (UTD). The combination of both yields a “virtual drive” through any scenario and allows optimization of antenna configurations without extensive measurement campaigns and without prototyping all configurations to be investigated. Additionally Virtual Drive provides a perfect repeatability of the testing environment.
{"title":"“Virtual Drive” physical layer simulations for Vehicle-to-Vehicle communication","authors":"L. Reichardt, T. Schipper, T. Zwick","doi":"10.1109/URSI-EMTS.2010.5637337","DOIUrl":"https://doi.org/10.1109/URSI-EMTS.2010.5637337","url":null,"abstract":"Future mobile communications, in the mean of Car-to-Car (C2C), Car-to-Infrastructure (C2I) or Vehicle-to-Vehicle (V2V) communication, will make use of multiple antenna systems like diversity or MIMO. Especially in multiple antenna systems finding the optimal antenna configuration in order to ensure the best performance is a very difficult task. Presently antennas in mobile communications systems, especially in cars, are selected in a rather expensive and time consuming test-drives, if at all. This will not be technically possible and affordable for multiple antenna systems in the future. Here a solution for this problem is demonstrated defined as Virtual Drive. In the Virtual Drive the quality of the antenna system is determined by simulating the mobile, driving through the EM-fields radiated from the transmitter. The multi-path propagation from the transmitter is calculated by a 3D ray-tracing tool, which is based on the theory of geometrical optics (GO) and the Uniform Theory of Diffraction (UTD). The combination of both yields a “virtual drive” through any scenario and allows optimization of antenna configurations without extensive measurement campaigns and without prototyping all configurations to be investigated. Additionally Virtual Drive provides a perfect repeatability of the testing environment.","PeriodicalId":404116,"journal":{"name":"2010 URSI International Symposium on Electromagnetic Theory","volume":"202 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":"133794341","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}
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