Pub Date : 2007-11-21DOI: 10.1109/ICEAA.2007.4387307
Y. Shkvarko
We address a new approach to solving radar imaging problems stated and treated as uncertain ill-conditioned inverse problems of nonparametric spatial power spectrum estimation via processing the finite number of independent observations of the degraded array data signals (one realization of the trajectory signal in the case of SAR). The idea is to adapt a statistically optimal minimum risk nonparametric power spectrum estimation approach to the radar imaging scenarios with model-level and system-level uncertainties. The proposed incorporation of the worst-case performance optimization-adapted robust regularization aggregated with the descriptive experiment design paradigm into the minimum risk nonparametric estimation strategy leads to a new unified doubly regularized minimum risk approach for robust adaptive high-resolution reconstructive imaging in the uncertain remote sensing scenarios.
{"title":"Unification of Descriptive Experiment Design and Worst-Case Performance Optimization-Adapted Regularization Paradigms for High-Resolution Reconstruction of Radar Imagery","authors":"Y. Shkvarko","doi":"10.1109/ICEAA.2007.4387307","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387307","url":null,"abstract":"We address a new approach to solving radar imaging problems stated and treated as uncertain ill-conditioned inverse problems of nonparametric spatial power spectrum estimation via processing the finite number of independent observations of the degraded array data signals (one realization of the trajectory signal in the case of SAR). The idea is to adapt a statistically optimal minimum risk nonparametric power spectrum estimation approach to the radar imaging scenarios with model-level and system-level uncertainties. The proposed incorporation of the worst-case performance optimization-adapted robust regularization aggregated with the descriptive experiment design paradigm into the minimum risk nonparametric estimation strategy leads to a new unified doubly regularized minimum risk approach for robust adaptive high-resolution reconstructive imaging in the uncertain remote sensing scenarios.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132363824","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387371
A. Imre, L. Ji, G. Csaba, A. Orlov, G. Bernstein, W. Porod
We report the fabrication of, and demonstrate logic functionality in, networks of magnetically-coupled, nanometer-scale magnets performing binary computation in a magnetic quantum-dot cellular automata (MQCA) system. MQCA is an all-magnetic logic that offers low power dissipation and high integration density of functional elements.
{"title":"Magnetic Logic based on Field-Coupled Nanomagnets","authors":"A. Imre, L. Ji, G. Csaba, A. Orlov, G. Bernstein, W. Porod","doi":"10.1109/ICEAA.2007.4387371","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387371","url":null,"abstract":"We report the fabrication of, and demonstrate logic functionality in, networks of magnetically-coupled, nanometer-scale magnets performing binary computation in a magnetic quantum-dot cellular automata (MQCA) system. MQCA is an all-magnetic logic that offers low power dissipation and high integration density of functional elements.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131534773","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387225
M. Baldauf, J. Pontes, J. Timmermann, W. Wiesbeck
A mobile phone equipped with a multiple antenna system is investigated with respect to its human exposure to electromagnetic fields. The channel conditions and the demanded capacity determine the required exictation voltages, which are passed to a commercial software tool. To get rid of the influence of various antenna distances to the shaped human head a dielectric cuboid is considered as absorbing medium. Utilizing MIMO techniques with channel knowledge at the transmitter allows a reduction of the exposure by some 95%.
{"title":"Mobile MIMO Phones and Their Human Exposure to Electromagnetic Fields","authors":"M. Baldauf, J. Pontes, J. Timmermann, W. Wiesbeck","doi":"10.1109/ICEAA.2007.4387225","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387225","url":null,"abstract":"A mobile phone equipped with a multiple antenna system is investigated with respect to its human exposure to electromagnetic fields. The channel conditions and the demanded capacity determine the required exictation voltages, which are passed to a commercial software tool. To get rid of the influence of various antenna distances to the shaped human head a dielectric cuboid is considered as absorbing medium. Utilizing MIMO techniques with channel knowledge at the transmitter allows a reduction of the exposure by some 95%.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131645389","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387305
K. Fukunaga, S. Kurahashi
We measured the complex permittivities of various polymeric materials used as the insulation layers of PCBs from 1 MHz to 110 GHz using various measurement systems. The data obtained by different methods are in good agreement and the permittivities are almost constant at frequencies higher than 10 GHz. The experimental results reveal that the anisotropy in the complex permittivities of insulating materials for PCBs is large owing to the inhomogeneous internal structure. The experimental results also proved that the permittivity is strongly influenced by humidity. By introducing these experimental results, we encourage studies of high frequency characteristics in solid dielectrics and insulating materials in PCB industries.
{"title":"Dielectric Properties of Printed Circuit Board Insulations at Microwaves and Millimetre Waves","authors":"K. Fukunaga, S. Kurahashi","doi":"10.1109/ICEAA.2007.4387305","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387305","url":null,"abstract":"We measured the complex permittivities of various polymeric materials used as the insulation layers of PCBs from 1 MHz to 110 GHz using various measurement systems. The data obtained by different methods are in good agreement and the permittivities are almost constant at frequencies higher than 10 GHz. The experimental results reveal that the anisotropy in the complex permittivities of insulating materials for PCBs is large owing to the inhomogeneous internal structure. The experimental results also proved that the permittivity is strongly influenced by humidity. By introducing these experimental results, we encourage studies of high frequency characteristics in solid dielectrics and insulating materials in PCB industries.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133796800","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387358
A. Nandgaonkar, S. Deosarkar
Microstrip Antennas (MSAs) have several advantages, including that they are light weight and small volume and that they can be made conformal to the host surface. In addition, MSAs are manufactured using printed circuit technology, so that mass production can be achieved at a low cost. In comparison to traditional antenna elements, however, the electrical performance of the basic microstrip antenna suffers from a number of serious drawbacks, e.g. narrow bandwidth; high feed network losses, poor cross polarization, and low power handling capacity. The major disadvantage of the microstrip-patch antenna is its inherently narrow impedance bandwidth of only a couple of percent. Intensive research is going on to develop bandwidth-enhancement techniques by keeping its size as small as possible. Accordingly, increasing the bandwidth of the MSA has been a primary goal of research in the field. We present here a compact two-layer electromagnetically coupled patch antenna with an impedance bandwidth of 35%. The radiation efficiency is obtained 90% in the operating band. The designed antenna is right-hand circularly polarized and operates in the 2.4 GHz ISM-band frequency The proposed structure has been initially optimized using IE3D software followed by experimental verification on Agilent Vector Network Analyzer, E5062A.
{"title":"Design of High Gain Two-Layer Electromagnetically Coupled Patch Antenna in the ISM Band","authors":"A. Nandgaonkar, S. Deosarkar","doi":"10.1109/ICEAA.2007.4387358","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387358","url":null,"abstract":"Microstrip Antennas (MSAs) have several advantages, including that they are light weight and small volume and that they can be made conformal to the host surface. In addition, MSAs are manufactured using printed circuit technology, so that mass production can be achieved at a low cost. In comparison to traditional antenna elements, however, the electrical performance of the basic microstrip antenna suffers from a number of serious drawbacks, e.g. narrow bandwidth; high feed network losses, poor cross polarization, and low power handling capacity. The major disadvantage of the microstrip-patch antenna is its inherently narrow impedance bandwidth of only a couple of percent. Intensive research is going on to develop bandwidth-enhancement techniques by keeping its size as small as possible. Accordingly, increasing the bandwidth of the MSA has been a primary goal of research in the field. We present here a compact two-layer electromagnetically coupled patch antenna with an impedance bandwidth of 35%. The radiation efficiency is obtained 90% in the operating band. The designed antenna is right-hand circularly polarized and operates in the 2.4 GHz ISM-band frequency The proposed structure has been initially optimized using IE3D software followed by experimental verification on Agilent Vector Network Analyzer, E5062A.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133600871","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387363
R. Maaskant, R. Mittra, A. Tijhuis
This paper describes a novel technique for generating the characteristic basis functions (CBFs) used to represent the surface currents on finite arrays of electrically interconnected antenna elements. The CBFs are high-level basis functions, defined on subdomains in which the original problem is divided. They are initially generated on extended subdomains; next, an easy-to-implement windowing technique is applied to them to truncate the undesired singularities in the currents generated at the artificial edges of the subdomains. The envelope of the window is trapezoidal in shape and we deliberately introduce a certain amount of overlap between the supports of the CBFs to ensure the continuity of the currents across the common interface between the adjacent subdomains. The accuracy and effectiveness of this method is demonstrated for a moderate as well as a large size array of tapered slot antennas (TSAs).
{"title":"Application of Trapezoidal-Shaped Characteristic Basis Functions to Arrays of Electrically Interconnected Antenna Elements","authors":"R. Maaskant, R. Mittra, A. Tijhuis","doi":"10.1109/ICEAA.2007.4387363","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387363","url":null,"abstract":"This paper describes a novel technique for generating the characteristic basis functions (CBFs) used to represent the surface currents on finite arrays of electrically interconnected antenna elements. The CBFs are high-level basis functions, defined on subdomains in which the original problem is divided. They are initially generated on extended subdomains; next, an easy-to-implement windowing technique is applied to them to truncate the undesired singularities in the currents generated at the artificial edges of the subdomains. The envelope of the window is trapezoidal in shape and we deliberately introduce a certain amount of overlap between the supports of the CBFs to ensure the continuity of the currents across the common interface between the adjacent subdomains. The accuracy and effectiveness of this method is demonstrated for a moderate as well as a large size array of tapered slot antennas (TSAs).","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116889515","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387316
G. Antonini
This paper presents a new methodology for the transient analysis of lossy transmission lines. The proposed model is derived from the solution the Telegrapher's equations in the framework of the Sturm-Liouville theory. The open-end impedance matrix is expressed in a series form as sum of infinite rational functions, derived by the series form of the Green's function. The pole-residue rational model can then be synthesized in an equivalent circuit or converted into a state space model which can be easily interfaced with circuit Spice-like solvers. The numerical results confirm the robustness of the proposed transmission line modelling technique.
{"title":"A Green's function-based method for the transient analysis of transmission lines","authors":"G. Antonini","doi":"10.1109/ICEAA.2007.4387316","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387316","url":null,"abstract":"This paper presents a new methodology for the transient analysis of lossy transmission lines. The proposed model is derived from the solution the Telegrapher's equations in the framework of the Sturm-Liouville theory. The open-end impedance matrix is expressed in a series form as sum of infinite rational functions, derived by the series form of the Green's function. The pole-residue rational model can then be synthesized in an equivalent circuit or converted into a state space model which can be easily interfaced with circuit Spice-like solvers. The numerical results confirm the robustness of the proposed transmission line modelling technique.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114911792","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387441
M. Saeed Tahvili, M. Sheikhi
In this paper, a distributed feedback (DFB) semiconductor laser amplifier (SLA) with nonuniform grating is studied for optical bistability behavior. The investigation is focused on distributed coupling coefficient (DCC) structures which have a corrugation with nonuniform depth along the cavity. A modified implementation of transfer-matrix method is used to take gain saturation and coupling coefficient variation along the DCC DFB structure into account. Wavelength dependence of optical bistability and the effect of gain-tuning in DCC DFB SLA's are demonstrated.
{"title":"Optical Bistability Behavior in a Distributed Coupling Coefficient Nonuniform DFB Semiconductor Laser Amplifier","authors":"M. Saeed Tahvili, M. Sheikhi","doi":"10.1109/ICEAA.2007.4387441","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387441","url":null,"abstract":"In this paper, a distributed feedback (DFB) semiconductor laser amplifier (SLA) with nonuniform grating is studied for optical bistability behavior. The investigation is focused on distributed coupling coefficient (DCC) structures which have a corrugation with nonuniform depth along the cavity. A modified implementation of transfer-matrix method is used to take gain saturation and coupling coefficient variation along the DCC DFB structure into account. Wavelength dependence of optical bistability and the effect of gain-tuning in DCC DFB SLA's are demonstrated.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121693943","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387490
M. Bialkowski, J. Encinar
The paper gives an overview of research activities on reflectarrays. It revisits the original concept of reflectarray and describes how its realization evolved over the last three decades. Fixed-beam and electronically steered varieties of this antenna are considered. Special considerations are devoted to a slot-coupled double-sided microstrip interconnect for use in reflectarrays and transmitarrays.
{"title":"Reflectarrays: Potentials and Challenges","authors":"M. Bialkowski, J. Encinar","doi":"10.1109/ICEAA.2007.4387490","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387490","url":null,"abstract":"The paper gives an overview of research activities on reflectarrays. It revisits the original concept of reflectarray and describes how its realization evolved over the last three decades. Fixed-beam and electronically steered varieties of this antenna are considered. Special considerations are devoted to a slot-coupled double-sided microstrip interconnect for use in reflectarrays and transmitarrays.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125665733","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 : 2007-11-21DOI: 10.1109/ICEAA.2007.4387393
B. P. de Hon, J. Arnold
We have developed FDTD boundary conditions based on discrete Green's function diakoptics for arbitrary multiply-connected 2D domains. The associated Z-domain boundary operator is symmetric, with an imaginary part that can be proved to be positive semi-definite on the upper half of the unit circle in the complex Z-plane. Through Schwarz' exterior formula an integral representation of this operator is obtained that is analytic outside that unit circle. A quadrature-rule based rational approximation of the operator corresponds to a self-consistent finite-lookback scheme in the discretised time domain. This scheme is demonstrably stable, in that only secular, non-growing, source-free solutions remain, which may be suppressed.
{"title":"Discrete Green's function diakoptics for stable FDTD interaction between multiply-connected domains","authors":"B. P. de Hon, J. Arnold","doi":"10.1109/ICEAA.2007.4387393","DOIUrl":"https://doi.org/10.1109/ICEAA.2007.4387393","url":null,"abstract":"We have developed FDTD boundary conditions based on discrete Green's function diakoptics for arbitrary multiply-connected 2D domains. The associated Z-domain boundary operator is symmetric, with an imaginary part that can be proved to be positive semi-definite on the upper half of the unit circle in the complex Z-plane. Through Schwarz' exterior formula an integral representation of this operator is obtained that is analytic outside that unit circle. A quadrature-rule based rational approximation of the operator corresponds to a self-consistent finite-lookback scheme in the discretised time domain. This scheme is demonstrably stable, in that only secular, non-growing, source-free solutions remain, which may be suppressed.","PeriodicalId":273595,"journal":{"name":"2007 International Conference on Electromagnetics in Advanced Applications","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122899954","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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