Pub Date : 2010-12-03DOI: 10.1109/ICEAA.2010.5653029
M. Bialkowski, A. R. Razali, Ashkan Boldaji, K. Cheng, P. Liu
This paper describes various miniaturization techniques of multiband antennas for portable transceivers. The considered techniques include folding, meandering and wrapping of the primary radiator. In addition, utilization of ground slots to widen the existing or generate new bands is described. These techniques are illustrated through design examples. Finally, a wideband antenna created by wrapping a quarter-elliptical monopole and a quarter-elliptical antenna with a complimentary slot are presented. These antennas cover all the popular wireless frequency bands in the 850MHz to 6GHz frequency spectrum with respect to the 6dB return loss reference. Full-wave EM simulations and experimental results for these compact multiband antennas are given.
{"title":"Miniaturization techniques of multiband antennas for portable transceivers","authors":"M. Bialkowski, A. R. Razali, Ashkan Boldaji, K. Cheng, P. Liu","doi":"10.1109/ICEAA.2010.5653029","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653029","url":null,"abstract":"This paper describes various miniaturization techniques of multiband antennas for portable transceivers. The considered techniques include folding, meandering and wrapping of the primary radiator. In addition, utilization of ground slots to widen the existing or generate new bands is described. These techniques are illustrated through design examples. Finally, a wideband antenna created by wrapping a quarter-elliptical monopole and a quarter-elliptical antenna with a complimentary slot are presented. These antennas cover all the popular wireless frequency bands in the 850MHz to 6GHz frequency spectrum with respect to the 6dB return loss reference. Full-wave EM simulations and experimental results for these compact multiband antennas are given.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133636921","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5653108
J. Kot
The Nyström method is a higher-order numerical method for solving a wide range of integral equations. While “Locally Corrected” Nyström methods can be developed for general integral equations in electromagnetism, the simpler Nyström method itself cannot be easily applied, except in particular cases. Here we present a heuristic approach to the solution of a volume integral equation for dielectric scattering using a simple higher-order Nyström method, and demonstrate the basic operation of the method by calculating the radar cross-section of a dielectric cube.
{"title":"A higher-order Nyström method for dielectric scattering","authors":"J. Kot","doi":"10.1109/ICEAA.2010.5653108","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653108","url":null,"abstract":"The Nyström method is a higher-order numerical method for solving a wide range of integral equations. While “Locally Corrected” Nyström methods can be developed for general integral equations in electromagnetism, the simpler Nyström method itself cannot be easily applied, except in particular cases. Here we present a heuristic approach to the solution of a volume integral equation for dielectric scattering using a simple higher-order Nyström method, and demonstrate the basic operation of the method by calculating the radar cross-section of a dielectric cube.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133914568","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5653874
J. Parker, M. Ferrara, J. Bracken, B. Himed
Traditional high-value monostatic imaging systems employ frequency-diverse pulses to form images from small synthetic apertures. In contrast, RF tomography utilizes a network of spatially diverse sensors to trade geometric diversity for bandwidth, permitting images to be formed with narrowband waveforms. Such a system could use inexpensive sensors with minimal ADC requirements, provide multiple viewpoints into urban canyons and other obscured environments, and offer graceful performance degradation under sensor attrition. However, numerous challenges must be overcome to field and operate such a system, including multistatic autofocus, precision timing requirements, and the development of appropriate image formation algorithms for large, sparsely populated synthetic apertures with anisotropic targets. AFRL has recently constructed an outdoor testing facility to explore these challenges with measured data. Preliminary experimental results are provided for this system, along with a description of remaining challenges and future research directions.
{"title":"Preliminary experimental results for RF tomography using distributed sensing","authors":"J. Parker, M. Ferrara, J. Bracken, B. Himed","doi":"10.1109/ICEAA.2010.5653874","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653874","url":null,"abstract":"Traditional high-value monostatic imaging systems employ frequency-diverse pulses to form images from small synthetic apertures. In contrast, RF tomography utilizes a network of spatially diverse sensors to trade geometric diversity for bandwidth, permitting images to be formed with narrowband waveforms. Such a system could use inexpensive sensors with minimal ADC requirements, provide multiple viewpoints into urban canyons and other obscured environments, and offer graceful performance degradation under sensor attrition. However, numerous challenges must be overcome to field and operate such a system, including multistatic autofocus, precision timing requirements, and the development of appropriate image formation algorithms for large, sparsely populated synthetic apertures with anisotropic targets. AFRL has recently constructed an outdoor testing facility to explore these challenges with measured data. Preliminary experimental results are provided for this system, along with a description of remaining challenges and future research directions.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131857175","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5653873
J. Sautner, Nithya Jayapratha, V. Metlushko
Most of magnetic nano-structures today are ultrathin or nanostructured films and multilayers. The main challenge is to find a suitable technology to integrate and to contact nanostructures in a reliable manner. Here, we investigate the problem of contact integration into functional 3-D devices and evaluate the influence of 3-D magnetic layer geometry on performance of magneto-electronic devices. Real devices are truly 3-dimensional structures. Their topography must absolutely be taken into consideration during the design phase since their inherent non-planarity will profoundly affect their magnetization profile. Our initial results strongly indicate that the “non-flatness” of magnetic layer strongly influences the possible magnetic states, alters the switching mechanism and leads to totally new behavior, which was not observed in classic 2-D thin film magnetic structures.
{"title":"Functional 3-D magnetic nanostructures","authors":"J. Sautner, Nithya Jayapratha, V. Metlushko","doi":"10.1109/ICEAA.2010.5653873","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653873","url":null,"abstract":"Most of magnetic nano-structures today are ultrathin or nanostructured films and multilayers. The main challenge is to find a suitable technology to integrate and to contact nanostructures in a reliable manner. Here, we investigate the problem of contact integration into functional 3-D devices and evaluate the influence of 3-D magnetic layer geometry on performance of magneto-electronic devices. Real devices are truly 3-dimensional structures. Their topography must absolutely be taken into consideration during the design phase since their inherent non-planarity will profoundly affect their magnetization profile. Our initial results strongly indicate that the “non-flatness” of magnetic layer strongly influences the possible magnetic states, alters the switching mechanism and leads to totally new behavior, which was not observed in classic 2-D thin film magnetic structures.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131862364","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5652281
Ming-lin Yang, X. Sheng
The finite element-boundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA) has shown to be very general and powerful for 3D scattering. To efficiently model cavity targets, a concave FE-BI-MLFMA is presented in this paper, which can significantly reduce the dispersion error from the FEM and improve the efficiency of FE-BI-MLFMA especially for nonuniform cavities. To eliminate the problem of slow convergence caused by concave surface, an efficient preconditioner based on the sparse approximate inverse (SAI) is constructed in this paper. Numerical experiments demonstrate the accuracy and efficiency of this SAI-preconditioned concave FE-BI-MLFMA for nonuniform deep and large cavites. Furthermore, the FE-BI-MLFMA is parallelized and has successfully compute the scattering from a conducting sphere with 1000 -wavelength diameter using more than 400 million unknowns.
{"title":"Parallel FE-BI-MLFMA for scattering by extremely large targets with cavities","authors":"Ming-lin Yang, X. Sheng","doi":"10.1109/ICEAA.2010.5652281","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5652281","url":null,"abstract":"The finite element-boundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA) has shown to be very general and powerful for 3D scattering. To efficiently model cavity targets, a concave FE-BI-MLFMA is presented in this paper, which can significantly reduce the dispersion error from the FEM and improve the efficiency of FE-BI-MLFMA especially for nonuniform cavities. To eliminate the problem of slow convergence caused by concave surface, an efficient preconditioner based on the sparse approximate inverse (SAI) is constructed in this paper. Numerical experiments demonstrate the accuracy and efficiency of this SAI-preconditioned concave FE-BI-MLFMA for nonuniform deep and large cavites. Furthermore, the FE-BI-MLFMA is parallelized and has successfully compute the scattering from a conducting sphere with 1000 -wavelength diameter using more than 400 million unknowns.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115198095","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5653856
C. Classen, B. Bandlow, R. Schuhmann
Whispering gallery modes of a flat dielectric disk are studied by means of analytical and numerical computational methods based on the finite integration technique. The results are compared to a high accuracy measurement. The frequently used semi-analytical method of effective refractive index has certain weaknesses in finding accurate eigenfrequencies and quality factors.
{"title":"Computational analysis of whispering gallery modes in flat dielectric disks","authors":"C. Classen, B. Bandlow, R. Schuhmann","doi":"10.1109/ICEAA.2010.5653856","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653856","url":null,"abstract":"Whispering gallery modes of a flat dielectric disk are studied by means of analytical and numerical computational methods based on the finite integration technique. The results are compared to a high accuracy measurement. The frequently used semi-analytical method of effective refractive index has certain weaknesses in finding accurate eigenfrequencies and quality factors.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114247011","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5653120
J. Puskely, Z. Nováček
A novel minimization method based on the principle of Fourier iterative method combining a global optimization with a compression method is used. The method uses conventional amplitude measurements on two surfaces placed in different distances from the antenna aperture. The global Particle Swarm Optimization (PSO) is used to minimize the fitness function (functional) and the Discrete Cosine Transform (DCT) is considered to reduce the number of unknown variables. The proposed method was applied for the reconstruction of the antenna array radiation patterns from data measured on the cylindrical surfaces.
{"title":"Far-field reconstruction based on compression method from cylindrical near-field phaseless measurements","authors":"J. Puskely, Z. Nováček","doi":"10.1109/ICEAA.2010.5653120","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653120","url":null,"abstract":"A novel minimization method based on the principle of Fourier iterative method combining a global optimization with a compression method is used. The method uses conventional amplitude measurements on two surfaces placed in different distances from the antenna aperture. The global Particle Swarm Optimization (PSO) is used to minimize the fitness function (functional) and the Discrete Cosine Transform (DCT) is considered to reduce the number of unknown variables. The proposed method was applied for the reconstruction of the antenna array radiation patterns from data measured on the cylindrical surfaces.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115163948","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5651478
H. Zhang, S. Y. Tan, W. W. J. Lee, H. Tan
This paper presents an experimental study on the microwave detection of spherical dielectric bodies exhibiting varying complex permittivity from the embedding lossy dielectric medium, simulating malignant tumors of different dielectric contrast from normal biological tissue. Measurements are performed using a flanged parallel-plate dielectric waveguide probe (PPDW) on phantom materials. Preliminary results demonstrate the potential of the PPDW to identify a malignant tumor embedded in normal tissue.
{"title":"On the microwave detection of dielectric bodies in a lossy medium with parallel-plate dielectric waveguide probe","authors":"H. Zhang, S. Y. Tan, W. W. J. Lee, H. Tan","doi":"10.1109/ICEAA.2010.5651478","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5651478","url":null,"abstract":"This paper presents an experimental study on the microwave detection of spherical dielectric bodies exhibiting varying complex permittivity from the embedding lossy dielectric medium, simulating malignant tumors of different dielectric contrast from normal biological tissue. Measurements are performed using a flanged parallel-plate dielectric waveguide probe (PPDW) on phantom materials. Preliminary results demonstrate the potential of the PPDW to identify a malignant tumor embedded in normal tissue.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123737656","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5648879
R. Valkonen, S. Myllymaki, A. Huttunen, J. Holopainen, J. Ilvonen, P. Vainikainen, H. Jantunen
In this paper, compensation of the effect of the user's finger on the operation of a mobile terminal antenna is studied, using antenna selection as the compensation method. A dual-element antenna is compared with a single-element antenna occupying the same total antenna volume. The results show that antenna selection can provide an improvement of at least 2 dB in total efficiency at GSM1800 frequency band when the antenna is under influence of the index finger of the user.
{"title":"Compensation of finger effect on a mobile terminal antenna by antenna selection","authors":"R. Valkonen, S. Myllymaki, A. Huttunen, J. Holopainen, J. Ilvonen, P. Vainikainen, H. Jantunen","doi":"10.1109/ICEAA.2010.5648879","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5648879","url":null,"abstract":"In this paper, compensation of the effect of the user's finger on the operation of a mobile terminal antenna is studied, using antenna selection as the compensation method. A dual-element antenna is compared with a single-element antenna occupying the same total antenna volume. The results show that antenna selection can provide an improvement of at least 2 dB in total efficiency at GSM1800 frequency band when the antenna is under influence of the index finger of the user.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123113001","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 : 2010-12-03DOI: 10.1109/ICEAA.2010.5653776
V. P. Bui, X. Wei, E. Li
This paper presents an advanced hybrid simulation technique to model the electromagnetic filed interactions between multi-transmitters and receivers in a complex closed environment; in which the method of moments/circuit method is used to accurately simulate the transceiver, and the longdistance electromagnetic field interaction is efficiently calculated by using the ray tracing technique based on the uniform theory of diffraction. The seamless combination between the circuit, numerical, and asymptotic approaches is the key to get accurate simulation results. Several numerical examples are presented to demonstrate the efficiency of the proposed hybrid technique.
{"title":"An efficient hybrid simulation technique for modeling the electromagnetic field propagation in a closed environment","authors":"V. P. Bui, X. Wei, E. Li","doi":"10.1109/ICEAA.2010.5653776","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653776","url":null,"abstract":"This paper presents an advanced hybrid simulation technique to model the electromagnetic filed interactions between multi-transmitters and receivers in a complex closed environment; in which the method of moments/circuit method is used to accurately simulate the transceiver, and the longdistance electromagnetic field interaction is efficiently calculated by using the ray tracing technique based on the uniform theory of diffraction. The seamless combination between the circuit, numerical, and asymptotic approaches is the key to get accurate simulation results. Several numerical examples are presented to demonstrate the efficiency of the proposed hybrid technique.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122725522","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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