Pub Date : 2010-12-03DOI: 10.1109/ICEAA.2010.5651680
S. Anderson
Increasing the power density incident on a target without raising the radiated power may offer a number of benefits to HF skywave radar systems. Among these is the prospect of detecting nonlinear echoes, which could greatly enhance detection in sea clutter. Other prospects include improved detection of low RCS targets and more effective use of sub-apertures for multiple simultaneous task operations. In this paper we review the physics underlying these missions and assess the potential of various approaches to concentrating energy in localized regions within the illuminated zone.
{"title":"Space-time focusing of HF skywave radar signals with application to nonlinear scattering phenomenology","authors":"S. Anderson","doi":"10.1109/ICEAA.2010.5651680","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5651680","url":null,"abstract":"Increasing the power density incident on a target without raising the radiated power may offer a number of benefits to HF skywave radar systems. Among these is the prospect of detecting nonlinear echoes, which could greatly enhance detection in sea clutter. Other prospects include improved detection of low RCS targets and more effective use of sub-apertures for multiple simultaneous task operations. In this paper we review the physics underlying these missions and assess the potential of various approaches to concentrating energy in localized regions within the illuminated zone.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"3 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":"128913649","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.2010.5652193
A. Coatanhay
The main purpose of this paper is to compare the numerical simulation of the electromagnetic scattering by a sea surface using a MoM approach and Nodal Discontinuous Galerkin Methods (NDGM).
本文的主要目的是比较用MoM方法和节点不连续伽辽金方法(NDGM)对海面电磁散射的数值模拟。
{"title":"Numerical modeling of the electromagnetic scattering by a sea surface: The MoM and Discontinuous Galerkin Method approaches","authors":"A. Coatanhay","doi":"10.1109/ICEAA.2010.5652193","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5652193","url":null,"abstract":"The main purpose of this paper is to compare the numerical simulation of the electromagnetic scattering by a sea surface using a MoM approach and Nodal Discontinuous Galerkin Methods (NDGM).","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"10 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":"115877169","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.2010.5653165
O. Shafalyuk, Y. Sirenko, P. D. Smith
In the paper, we solve the so-called open problems for electromagnetic field distribution in axially symmetrical open resonant structures. We construct the Exact Absorbing Conditions that allow efficient truncating the computational domain. Proof of equivalency between these initial and modified problems will also be provided.
{"title":"Exact absorbing conditions for FDTD analysis of axially-symmetrical open structures","authors":"O. Shafalyuk, Y. Sirenko, P. D. Smith","doi":"10.1109/ICEAA.2010.5653165","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653165","url":null,"abstract":"In the paper, we solve the so-called open problems for electromagnetic field distribution in axially symmetrical open resonant structures. We construct the Exact Absorbing Conditions that allow efficient truncating the computational domain. Proof of equivalency between these initial and modified problems will also be provided.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"319 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":"124524180","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.2010.5650011
K. Kagoshima, A. Kagaya, S. Obote
Decoupling and matching feeding networks are considerably interested for small wireless terminals to enhance their abilities in the application for MIMO systems. This paper describes various kinds of decoupling and matching feeding networks and derives the formulas for determining the network elements explicitly. Numerical results are presented to ensure the formula for each decoupling and matching feeding network. Discussions on the difference of the networks are also presented.
{"title":"Investigations on decoupling and matching feeding networks for a MIMO array antenna","authors":"K. Kagoshima, A. Kagaya, S. Obote","doi":"10.1109/ICEAA.2010.5650011","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5650011","url":null,"abstract":"Decoupling and matching feeding networks are considerably interested for small wireless terminals to enhance their abilities in the application for MIMO systems. This paper describes various kinds of decoupling and matching feeding networks and derives the formulas for determining the network elements explicitly. Numerical results are presented to ensure the formula for each decoupling and matching feeding network. Discussions on the difference of the networks are also presented.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"173 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":"114435855","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.2010.5653237
R. Mildren
An investigation of a crystalline Raman laser pumped perpendicular to the Raman resonator axis is reported. A rectangular prism of potassium gadolinium tungstate crystal is pumped at 90° to the Raman laser axis using a line focused 532 nm pump laser of pulse duration 10 ns. The Raman laser threshold was 6.1 mJ and at 12 mJ pump energy a maximum output energy of 2.7 mJ was obtained with a slope efficiency of 46%. Th e threshold is compared with theoretical predictions, which suggest that gain and laser threshold are largely independent of pump direction. The results highlight significant potential for Raman lasers with enhanced degrees of flexibility and increased power.
{"title":"Characteristics of a side pumped tungstate Raman laser","authors":"R. Mildren","doi":"10.1109/ICEAA.2010.5653237","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653237","url":null,"abstract":"An investigation of a crystalline Raman laser pumped perpendicular to the Raman resonator axis is reported. A rectangular prism of potassium gadolinium tungstate crystal is pumped at 90° to the Raman laser axis using a line focused 532 nm pump laser of pulse duration 10 ns. The Raman laser threshold was 6.1 mJ and at 12 mJ pump energy a maximum output energy of 2.7 mJ was obtained with a slope efficiency of 46%. Th e threshold is compared with theoretical predictions, which suggest that gain and laser threshold are largely independent of pump direction. The results highlight significant potential for Raman lasers with enhanced degrees of flexibility and increased power.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"140 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":"114604816","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.2010.5651876
Yuanwei Jin, Nicholas OrDonoughue, José M. F. Moura
EM multipath propagation is common in radar and wireless communications. Most radar systems are designed assuming line-of-sight (LOS), not multipath. In this paper, we extend our prior work on Multi-Input Multi-Output (MIMO) radar in the absence of interference [1], to consider MIMO radar detection in high clutter. We develop a subspace MIMO target model and a statistical model for MIMO radar clutter that accounts for the spatial and spectral properties of radar returns. We show that, using orthogonal waveform signaling, the time reversal MIMO radar yields higher detection performance than conventional statistical MIMO radar in high clutter.
{"title":"Time reversal adaptive waveform in MIMO radar","authors":"Yuanwei Jin, Nicholas OrDonoughue, José M. F. Moura","doi":"10.1109/ICEAA.2010.5651876","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5651876","url":null,"abstract":"EM multipath propagation is common in radar and wireless communications. Most radar systems are designed assuming line-of-sight (LOS), not multipath. In this paper, we extend our prior work on Multi-Input Multi-Output (MIMO) radar in the absence of interference [1], to consider MIMO radar detection in high clutter. We develop a subspace MIMO target model and a statistical model for MIMO radar clutter that accounts for the spatial and spectral properties of radar returns. We show that, using orthogonal waveform signaling, the time reversal MIMO radar yields higher detection performance than conventional statistical MIMO radar in high clutter.","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":"122132518","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.2010.5652981
Canhui Chen, E. Yung
A novel dual-band linearly polarized antenna with conical beam is proposed in this paper. By using two isolated symmetrical slots and the central feeding line, conical-beam radiation patterns will be generated. In addition, due to its coherent structure and the quasi-T shape feeding line, dualband operations can be attained. The measured result shows that the antenna has the impedance bandwidths of 1.8% for the lower band and 2.6% for the upper band. The radiation pattern characteristic will also be presented.
{"title":"Dual-band linearly-polarized slot antenna with conical beam","authors":"Canhui Chen, E. Yung","doi":"10.1109/ICEAA.2010.5652981","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5652981","url":null,"abstract":"A novel dual-band linearly polarized antenna with conical beam is proposed in this paper. By using two isolated symmetrical slots and the central feeding line, conical-beam radiation patterns will be generated. In addition, due to its coherent structure and the quasi-T shape feeding line, dualband operations can be attained. The measured result shows that the antenna has the impedance bandwidths of 1.8% for the lower band and 2.6% for the upper band. The radiation pattern characteristic will also be presented.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"470 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120881666","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.2010.5652963
V. Rose, J. Freeland
The combination of synchrotron x-rays with scanning tunneling microscopy provides a promising new path towards the imaging of nanoscale structures with chemical, electronic, and magnetic contrast. While a scanning probe provides the high spatial resolution measuring x-ray magnetic circular dichroism allows the direct quantification of magnetic moments. This capability has the potential to broaden and deepen the general understanding of nanomagnetism.
{"title":"A new concept for quantitative nanoscale imaging with magnetic contrast: Synchrotron x-ray enhanced scanning tunneling microscopy","authors":"V. Rose, J. Freeland","doi":"10.1109/ICEAA.2010.5652963","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5652963","url":null,"abstract":"The combination of synchrotron x-rays with scanning tunneling microscopy provides a promising new path towards the imaging of nanoscale structures with chemical, electronic, and magnetic contrast. While a scanning probe provides the high spatial resolution measuring x-ray magnetic circular dichroism allows the direct quantification of magnetic moments. This capability has the potential to broaden and deepen the general understanding of nanomagnetism.","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":"123971719","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.2010.5653841
B. P. de Hon, J. Arnold
In Green's function diakoptics, wave-field interactions between disjoint domains in space are described in terms of interacting multi-port subsystems. In addition to integral-equation based Green's function diakoptics for time-harmonic fields, a demonstrably stable discrete space-time Green's function diakoptics scheme has been reported to be effective for proximate regions. For distant regions it is necessary to retain a long field history. Upon considering a diakoptics toy problem involving two disjoint domains consisting of a single point each, the resulting boundary operator may be expressed in terms of two distinct discrete Green's functions only, describing the intra- and inter-domain unit-source field responses, respectively. There are various integral representations and asymptotic expansions for the discrete Z-domain Green's functions, and it is even possible to construct representations for the discrete space-time Green's functions consisting of nested finite sums, which turn out to be difficult to evaluate due to severe cancellations.
{"title":"Discrete Green's function diakoptics — A toy problem","authors":"B. P. de Hon, J. Arnold","doi":"10.1109/ICEAA.2010.5653841","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653841","url":null,"abstract":"In Green's function diakoptics, wave-field interactions between disjoint domains in space are described in terms of interacting multi-port subsystems. In addition to integral-equation based Green's function diakoptics for time-harmonic fields, a demonstrably stable discrete space-time Green's function diakoptics scheme has been reported to be effective for proximate regions. For distant regions it is necessary to retain a long field history. Upon considering a diakoptics toy problem involving two disjoint domains consisting of a single point each, the resulting boundary operator may be expressed in terms of two distinct discrete Green's functions only, describing the intra- and inter-domain unit-source field responses, respectively. There are various integral representations and asymptotic expansions for the discrete Z-domain Green's functions, and it is even possible to construct representations for the discrete space-time Green's functions consisting of nested finite sums, which turn out to be difficult to evaluate due to severe cancellations.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"126 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":"125770116","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.2010.5651557
I. Kohlberg, S. Hemmady
This paper examines the applications of statistical physics-stochastic processes, ergodic principles, the use of nonlinear dynamic state equations and chaos, and the Wiener-Khintchine theorem to better explain how Intentional ElectroMagnetic Interference (IEMI) disrupts the performance of feedback and hybrid electronic systems such as control systems, power electronics and SCADAs. The origin of spurious “almost-random” voltage fluctuations induced within a complicated enclosure when exposed to EM fluences is explained, and a mathematical formulation to quantify the energy coupled into a complicated cavity under High Power Microwave stress is derived.
{"title":"Principles of statistical physics as applied to EMC","authors":"I. Kohlberg, S. Hemmady","doi":"10.1109/ICEAA.2010.5651557","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5651557","url":null,"abstract":"This paper examines the applications of statistical physics-stochastic processes, ergodic principles, the use of nonlinear dynamic state equations and chaos, and the Wiener-Khintchine theorem to better explain how Intentional ElectroMagnetic Interference (IEMI) disrupts the performance of feedback and hybrid electronic systems such as control systems, power electronics and SCADAs. The origin of spurious “almost-random” voltage fluctuations induced within a complicated enclosure when exposed to EM fluences is explained, and a mathematical formulation to quantify the energy coupled into a complicated cavity under High Power Microwave stress is derived.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"11 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":"129747661","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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