Pub Date : 2015-03-05DOI: 10.1109/COMPEM.2015.7052581
C. Zekios, P. Allilomes, G. Kyriacou
Recently we have proposed a finite element based eigenanalysis for lossy and unbounded structures. Our present effort aims at the validation of this technique for the study of complex radiating structures like the cavity backed type. The typical Absorbing Boundary Condition (ABC) of 1st kind is employed, while finite conductivity is introduced at the metallic parts of the studied structure. The spurious modes are being suppressed by the enforcement of "divergence-free" constraint equations in the whole domain. It is proved in the current work that the non-physical modes restriction of the solution domain is achieved only by the projection of the seeding vector in the null space of the irrotational field, during the linearization procedure.
{"title":"Eigenanalysis of open-radiating microwave structures with efficient suppression of spurious modes","authors":"C. Zekios, P. Allilomes, G. Kyriacou","doi":"10.1109/COMPEM.2015.7052581","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052581","url":null,"abstract":"Recently we have proposed a finite element based eigenanalysis for lossy and unbounded structures. Our present effort aims at the validation of this technique for the study of complex radiating structures like the cavity backed type. The typical Absorbing Boundary Condition (ABC) of 1st kind is employed, while finite conductivity is introduced at the metallic parts of the studied structure. The spurious modes are being suppressed by the enforcement of \"divergence-free\" constraint equations in the whole domain. It is proved in the current work that the non-physical modes restriction of the solution domain is achieved only by the projection of the seeding vector in the null space of the irrotational field, during the linearization procedure.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"7 1","pages":"132-134"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74663878","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052613
Dawei Song
For optical waveguides with high index-contrast and sharp corners, the mode matching method can be used when the interfaces are only in vertical and horizontal directions. As an efficient alternative to the classical mode matching method, the pseudospectral modal method (PSMM) for diffraction gratings has recently been reformulated as a full-vectorial waveguide mode solver. In this paper, we apply the PSMM mode solver to a classical rib waveguide benchmark problem. The results show that the PSMM can give extremely high accuracy.
{"title":"Accurate analysis of a rib waveguide by pseudospectral modal method","authors":"Dawei Song","doi":"10.1109/COMPEM.2015.7052613","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052613","url":null,"abstract":"For optical waveguides with high index-contrast and sharp corners, the mode matching method can be used when the interfaces are only in vertical and horizontal directions. As an efficient alternative to the classical mode matching method, the pseudospectral modal method (PSMM) for diffraction gratings has recently been reformulated as a full-vectorial waveguide mode solver. In this paper, we apply the PSMM mode solver to a classical rib waveguide benchmark problem. The results show that the PSMM can give extremely high accuracy.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"112 1","pages":"224-226"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80573266","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052533
W. Chew
Electromagnetics and Maxwell's equations have been instrumental in the conception of many electrical engineering technologies. It the beginning, it was telegraphy, and rotating machineries. Over the years, electromagnetics has given rise to numerous technologies like wireless communications, antennas, radar, and masers. On the optics side, simplified ray optics theory was used to design lenses and focusing systems. As many optical systems can be described by ray optics approximations, the first area that requires the full solution of Maxwell's equations is in microwave engineering, antenna design, and remote and subsurface sensing. Hence, there were pressing needs to design better antenna systems for communication, radar for target identification, and radio waves for remote sensing. While closed form solutions offered some physics insight, approximate solutions were invoked to further expand the insight of designers and engineers. When approximation solutions were exhausted, numerical methods or computational electromagnetics (CEM) were developed to further aid designers and engineers. As demand for numerical methods looms, fast and efficient methods of solving Maxwell's equations become a popular topic of research. There are essentially two classes of solvers for Maxwell's equations: differential equation solvers and integral equation solvers. While differential equation solvers use more unknowns than integral equation solvers, they are easy to implement and to maintain. Integral equation solvers, on the other hand, use fewer unknowns, but are more difficult to implement. They also yield dense matrix systems that are expensive to solve and store. However, the advent of fast solvers has greatly expedited their solution efficiency. As of this point, dense matrix systems with over three billion unknowns have been solved using fast solvers. Also, the path to large scale computing requires the use of iterative solvers. Over time, as the demand for CEM solvers grows, more complex structures with a disproportionate number of unknowns need to be solved. They give rise to ill-conditioned matrix systems. Hence, preconditioners or domain decomposition methods are designed to reduce the ill conditioning of matrix system. The preconditioners will greatly expedite iterative solutions to these problems. Maxwell's equations are also intimately related to mathematical geometry and to quantum physics. Differential geometry concepts can be invoked to help in the selection of basis and testing functions in finding the matrix representations of Maxwell operators. Furthermore, even when quantum theory is invoked in the quantization of electromagnetic fields, the fields are still governed by Maxwell's equations. Therefore, solutions of Maxwell's equations are needed even in the quantum regime. Since photons play an important role in the manipulation of quantum information, the solutions of Maxwell's equations will be instrumental even in quantum optics or quantum elec
{"title":"Keynote speaker 1: Computational electromagnetics: Past, present, and future","authors":"W. Chew","doi":"10.1109/COMPEM.2015.7052533","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052533","url":null,"abstract":"Electromagnetics and Maxwell's equations have been instrumental in the conception of many electrical engineering technologies. It the beginning, it was telegraphy, and rotating machineries. Over the years, electromagnetics has given rise to numerous technologies like wireless communications, antennas, radar, and masers. On the optics side, simplified ray optics theory was used to design lenses and focusing systems. As many optical systems can be described by ray optics approximations, the first area that requires the full solution of Maxwell's equations is in microwave engineering, antenna design, and remote and subsurface sensing. Hence, there were pressing needs to design better antenna systems for communication, radar for target identification, and radio waves for remote sensing. While closed form solutions offered some physics insight, approximate solutions were invoked to further expand the insight of designers and engineers. When approximation solutions were exhausted, numerical methods or computational electromagnetics (CEM) were developed to further aid designers and engineers. As demand for numerical methods looms, fast and efficient methods of solving Maxwell's equations become a popular topic of research. There are essentially two classes of solvers for Maxwell's equations: differential equation solvers and integral equation solvers. While differential equation solvers use more unknowns than integral equation solvers, they are easy to implement and to maintain. Integral equation solvers, on the other hand, use fewer unknowns, but are more difficult to implement. They also yield dense matrix systems that are expensive to solve and store. However, the advent of fast solvers has greatly expedited their solution efficiency. As of this point, dense matrix systems with over three billion unknowns have been solved using fast solvers. Also, the path to large scale computing requires the use of iterative solvers. Over time, as the demand for CEM solvers grows, more complex structures with a disproportionate number of unknowns need to be solved. They give rise to ill-conditioned matrix systems. Hence, preconditioners or domain decomposition methods are designed to reduce the ill conditioning of matrix system. The preconditioners will greatly expedite iterative solutions to these problems. Maxwell's equations are also intimately related to mathematical geometry and to quantum physics. Differential geometry concepts can be invoked to help in the selection of basis and testing functions in finding the matrix representations of Maxwell operators. Furthermore, even when quantum theory is invoked in the quantization of electromagnetic fields, the fields are still governed by Maxwell's equations. Therefore, solutions of Maxwell's equations are needed even in the quantum regime. Since photons play an important role in the manipulation of quantum information, the solutions of Maxwell's equations will be instrumental even in quantum optics or quantum elec","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"22 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84346896","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052547
Fu Liu, Pengjiang Wei, Zheng Chang, G. Hu, Jensen Li
Quasiconformal maps have been utilized for generating transformation optical devices with a range of applications including invisibility cloaks, waveguide benders, couplers, surface-conformal lenses and antennas. Here, we discuss their generation by numerically solving the Poisson's equation where the analytic solution of a typical electrostatic problem in the virtual space acts as a seed in numerically generating a quasiconformal map with a transformed shape of boundary. Two examples about capacitor under external voltage and a point charge in a cavity are given.
{"title":"Quasiconformal maps in transformation optics and their electrostatic analogs","authors":"Fu Liu, Pengjiang Wei, Zheng Chang, G. Hu, Jensen Li","doi":"10.1109/COMPEM.2015.7052547","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052547","url":null,"abstract":"Quasiconformal maps have been utilized for generating transformation optical devices with a range of applications including invisibility cloaks, waveguide benders, couplers, surface-conformal lenses and antennas. Here, we discuss their generation by numerically solving the Poisson's equation where the analytic solution of a typical electrostatic problem in the virtual space acts as a seed in numerically generating a quasiconformal map with a transformed shape of boundary. Two examples about capacitor under external voltage and a point charge in a cavity are given.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"63 1","pages":"38-40"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91045651","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052615
X. Fang, Ka Ki Ng, K. Leung
A strip-fed wideband circularly polarized (CP) dielectric resonator antenna (DRA) is investigated in this paper. The wideband design makes use of the quasi-TE111 and -TE113 modes of the rectangular DRA. To generate CP fields, two opposite corners of the rectangular DRA are truncated at 45°. A groove and two parasitic strips are introduced to tune the axial ratio (AR) of the antenna. Measured results show that a wide AR bandwidth of 16.3 % can be achieved. The reflection coefficient, AR radiation pattern, and antenna gain of the DRA are studied using ANSYS HFSS. Reasonable agreement between the measured and simulated results is observed.
{"title":"On a wideband circularly polarized dielectric resonator antenna using a higher-order mode","authors":"X. Fang, Ka Ki Ng, K. Leung","doi":"10.1109/COMPEM.2015.7052615","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052615","url":null,"abstract":"A strip-fed wideband circularly polarized (CP) dielectric resonator antenna (DRA) is investigated in this paper. The wideband design makes use of the quasi-TE111 and -TE113 modes of the rectangular DRA. To generate CP fields, two opposite corners of the rectangular DRA are truncated at 45°. A groove and two parasitic strips are introduced to tune the axial ratio (AR) of the antenna. Measured results show that a wide AR bandwidth of 16.3 % can be achieved. The reflection coefficient, AR radiation pattern, and antenna gain of the DRA are studied using ANSYS HFSS. Reasonable agreement between the measured and simulated results is observed.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"15 1","pages":"230-231"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90513546","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052602
Zherui Yu, Haogang Wang, Jiancheng Shi, L. He
In this paper, we propose a new sampling algorithm combined with multilevel UV(MLUV) factorization method to calculate the scattering from Gaussian random rough surface with exponential correlation function. The new sampling algorithm is based on the steepness of patch pairs which support the basis functions. The numerical analyses in this paper show that the proposed algorithm significantly improves the accuracy of the UV approximation of matrix ZK.
{"title":"A new sampling algorithm used in multilevel UV factorization method for scattering from random rough surface","authors":"Zherui Yu, Haogang Wang, Jiancheng Shi, L. He","doi":"10.1109/COMPEM.2015.7052602","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052602","url":null,"abstract":"In this paper, we propose a new sampling algorithm combined with multilevel UV(MLUV) factorization method to calculate the scattering from Gaussian random rough surface with exponential correlation function. The new sampling algorithm is based on the steepness of patch pairs which support the basis functions. The numerical analyses in this paper show that the proposed algorithm significantly improves the accuracy of the UV approximation of matrix ZK.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"1 1","pages":"192-194"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88568628","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052565
Shan Xing, Yilong Lu
This paper presents a study of various types of radar array architectures for low cost radar antennas with digital beamforming (BDF) capabilities. In addition to popular one-way and two-way beamforming, the emerging synthetic array radar (SAR)-like DBF and multiple-input-multiple-output (MEMO) DBF are examined with beamforming equations. New simple approximation formulae about half-power beamwidth (HPBW) estimation for SAR-like array and MIMO array are proposed for easier design reference. The comparison study shows that the SAR-like DBF or MEMO DBF can achieve much better angular higher resolution than the conventional oneway or twoway beamforming techniques.
{"title":"Types and comparison of low cost radar beamforming arrays","authors":"Shan Xing, Yilong Lu","doi":"10.1109/COMPEM.2015.7052565","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052565","url":null,"abstract":"This paper presents a study of various types of radar array architectures for low cost radar antennas with digital beamforming (BDF) capabilities. In addition to popular one-way and two-way beamforming, the emerging synthetic array radar (SAR)-like DBF and multiple-input-multiple-output (MEMO) DBF are examined with beamforming equations. New simple approximation formulae about half-power beamwidth (HPBW) estimation for SAR-like array and MIMO array are proposed for easier design reference. The comparison study shows that the SAR-like DBF or MEMO DBF can achieve much better angular higher resolution than the conventional oneway or twoway beamforming techniques.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"55 1","pages":"87-88"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81121306","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052644
X. Niu, Z. Nie, X. Que, Shiquan He
In this paper, scattering from hypersonic vehicles covered with the plasma sheath has been studied by the multilayer thin dielectric sheet (ML-TDS) approximation method. Single-layer model and multi-layer model are used to solve the scattering problem with the thinner and thicker plasma sheath, respectively. A few unknowns have been needed to model the hypersonic vehicles covered with the plasma sheath. A waverider-shaped vehicle model has been analyzed in the paper.
{"title":"ML-TDS analysis of scattering from hypersonic vehicles covered with plasma sheath","authors":"X. Niu, Z. Nie, X. Que, Shiquan He","doi":"10.1109/COMPEM.2015.7052644","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052644","url":null,"abstract":"In this paper, scattering from hypersonic vehicles covered with the plasma sheath has been studied by the multilayer thin dielectric sheet (ML-TDS) approximation method. Single-layer model and multi-layer model are used to solve the scattering problem with the thinner and thicker plasma sheath, respectively. A few unknowns have been needed to model the hypersonic vehicles covered with the plasma sheath. A waverider-shaped vehicle model has been analyzed in the paper.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"578 1","pages":"309-311"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78510517","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052617
L. Feng, K. Leung
The omnidirectional rectangular dielectric resonator (DR) antenna (DRA) using its higher-order quasi-TM015 mode is proposed for the gain enhancement. It was designed, fabricated and measured for 5.8-GHz WLAN applications. Its measured bandwidth and antenna gain of the proposed DRA are 4.84% and 3.63 dBi, respectively.
{"title":"Gain enhanced omnidirectional rectangular dielectric resonator antenna","authors":"L. Feng, K. Leung","doi":"10.1109/COMPEM.2015.7052617","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052617","url":null,"abstract":"The omnidirectional rectangular dielectric resonator (DR) antenna (DRA) using its higher-order quasi-TM015 mode is proposed for the gain enhancement. It was designed, fabricated and measured for 5.8-GHz WLAN applications. Its measured bandwidth and antenna gain of the proposed DRA are 4.84% and 3.63 dBi, respectively.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"30 1","pages":"235-236"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82838063","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 : 2015-03-05DOI: 10.1109/COMPEM.2015.7052555
E. Moradi, K. Koski, M. Hasani, Y. Rahmat-Samii, L. Ukkonen
In this paper we analyze the design and realization of wearable and implantable antennas meant for wireless body-centric systems. Studied wearable antennas exploit electro-textiles, including embroidered textiles and conductive fabrics, for the light-weight and transparent integration with daily clothing. We also present mm-sized implantable loop antennas that are capable of providing electromagnetic power to implant devices from an external on-body loop antenna through near field inductive link.
{"title":"Antenna design considerations for far field and near field wireless body-centric systems","authors":"E. Moradi, K. Koski, M. Hasani, Y. Rahmat-Samii, L. Ukkonen","doi":"10.1109/COMPEM.2015.7052555","DOIUrl":"https://doi.org/10.1109/COMPEM.2015.7052555","url":null,"abstract":"In this paper we analyze the design and realization of wearable and implantable antennas meant for wireless body-centric systems. Studied wearable antennas exploit electro-textiles, including embroidered textiles and conductive fabrics, for the light-weight and transparent integration with daily clothing. We also present mm-sized implantable loop antennas that are capable of providing electromagnetic power to implant devices from an external on-body loop antenna through near field inductive link.","PeriodicalId":6530,"journal":{"name":"2015 IEEE International Conference on Computational Electromagnetics","volume":"79 1","pages":"59-60"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88845963","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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