Pub Date : 2010-12-03DOI: 10.1109/ICEAA.2010.5653141
P. Feil, F. Bauer
For some applications the use of metal backed substrates is advantageous. The solid backside-metallization provides a good heatsink and gives the possibility to produce MMIC-cavities by milling. However, the circuit design is bounded to one layer, and therefore the choice of suitable waveguide transitions is limited. Especially if right-angle transitions are needed, no structures are known to the authors that can be produced easily by single-layer etching and milling processes. In this contribution two microstrip line (MSL) to rectangular waveguide transitions are presented that can be used with metal backed substrates. One of the transitions can be fabricated even without via holes. Designs are presented for the E-band and the Ka-band, but the principles can be scaled to other frequency ranges.
{"title":"Two right-angle microstrip to waveguide transitions suitable for metal backed substrates","authors":"P. Feil, F. Bauer","doi":"10.1109/ICEAA.2010.5653141","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653141","url":null,"abstract":"For some applications the use of metal backed substrates is advantageous. The solid backside-metallization provides a good heatsink and gives the possibility to produce MMIC-cavities by milling. However, the circuit design is bounded to one layer, and therefore the choice of suitable waveguide transitions is limited. Especially if right-angle transitions are needed, no structures are known to the authors that can be produced easily by single-layer etching and milling processes. In this contribution two microstrip line (MSL) to rectangular waveguide transitions are presented that can be used with metal backed substrates. One of the transitions can be fabricated even without via holes. Designs are presented for the E-band and the Ka-band, but the principles can be scaled to other frequency ranges.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"17 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":"128067162","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.2010.5653604
T. Kaufmann, C. Engstrom, C. Fumeaux
The concept of an adaptive meshless eigenvalue solver is presented and implemented for two-dimensional structures. Based on radial basis functions, eigenmodes are calculated in a collocation approach for the second-order wave equation. This type of meshless method promises highly accurate results with the simplicity of a node-based collocation approach. Thus, when changing the discrete representation of a physical model, only node locations have to be adapted, hence avoiding the numerical overhead of handling an explicit mesh topology. The accuracy of the method comes at a cost of dealing with poorly-conditioned matrices. This is circumvented by applying a leave-one-out-cross-validation optimization algorithm to get stable results. A node adaptivity algorithm is presented to efficiently refine an initially coarse discretization. The convergence is evaluated in two numerical examples with analytical solutions. The most relevant parameter of the adaptation algorithm is numerically investigated and its influence on the convergence rate examined.
{"title":"Residual-based adaptive refinement for meshless eigenvalue solvers","authors":"T. Kaufmann, C. Engstrom, C. Fumeaux","doi":"10.1109/ICEAA.2010.5653604","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653604","url":null,"abstract":"The concept of an adaptive meshless eigenvalue solver is presented and implemented for two-dimensional structures. Based on radial basis functions, eigenmodes are calculated in a collocation approach for the second-order wave equation. This type of meshless method promises highly accurate results with the simplicity of a node-based collocation approach. Thus, when changing the discrete representation of a physical model, only node locations have to be adapted, hence avoiding the numerical overhead of handling an explicit mesh topology. The accuracy of the method comes at a cost of dealing with poorly-conditioned matrices. This is circumvented by applying a leave-one-out-cross-validation optimization algorithm to get stable results. A node adaptivity algorithm is presented to efficiently refine an initially coarse discretization. The convergence is evaluated in two numerical examples with analytical solutions. The most relevant parameter of the adaptation algorithm is numerically investigated and its influence on the convergence rate examined.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"1 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":"130018582","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.2010.5650929
Zhi-Hang Wu, Wenxun Zhang
The printed compound air-fed array (PCAFA) is an improved Fabry-Perot resonator (FPR) antenna, which exhibits better performance than traditional FPR antenna, by means of the non-uniform phase and magnitude of field distribution on aperture are partly compensated in design. In this paper a kind of circularly polarized (CP) PCAFA antenna is proposed and studied, in which the FSS cover is composed of square patches with tapered size and the HIS base is composed of mushroom-type rectangular patches with inversely tapered patch size. The CP radiation is generated by a simple conner-fed rectangular patch radiator which is embedded in the centre of the base. This CP PCAFA antenna owns the features of feeding simplicity, low-profile structure, high gain and high aperture efficiency. The design procedure and example is presented.
{"title":"A circularly polarized printed compound air-fed array antenna","authors":"Zhi-Hang Wu, Wenxun Zhang","doi":"10.1109/ICEAA.2010.5650929","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5650929","url":null,"abstract":"The printed compound air-fed array (PCAFA) is an improved Fabry-Perot resonator (FPR) antenna, which exhibits better performance than traditional FPR antenna, by means of the non-uniform phase and magnitude of field distribution on aperture are partly compensated in design. In this paper a kind of circularly polarized (CP) PCAFA antenna is proposed and studied, in which the FSS cover is composed of square patches with tapered size and the HIS base is composed of mushroom-type rectangular patches with inversely tapered patch size. The CP radiation is generated by a simple conner-fed rectangular patch radiator which is embedded in the centre of the base. This CP PCAFA antenna owns the features of feeding simplicity, low-profile structure, high gain and high aperture efficiency. The design procedure and example is presented.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"37 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":"129016041","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.2010.5653131
M. Okiyokota, T. Yasuzumi, Y. Kazama, O. Hashimoto
In this paper, a phased array antenna for a linearly polarized wave is proposed for mobile satellite communications antennas. An element antenna consists of two loop antennas concentrically located on a dielectric substrate with a reflector and these loop antennas work at dominant and second mode resonant frequencies. Firstly, characteristics of each loop antenna fed by a microstrip transmission line (MSL) are simulated and measured to investigate fundamental radiation characteristics of these antennas. Next, a 16-element linear array antenna is simulated and measured. It is shown that the proposed antenna is suitable for the mobile satellite communications antenna.
{"title":"Beam secanning characteristics on 16-element array antenna using double-loop antenna","authors":"M. Okiyokota, T. Yasuzumi, Y. Kazama, O. Hashimoto","doi":"10.1109/ICEAA.2010.5653131","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653131","url":null,"abstract":"In this paper, a phased array antenna for a linearly polarized wave is proposed for mobile satellite communications antennas. An element antenna consists of two loop antennas concentrically located on a dielectric substrate with a reflector and these loop antennas work at dominant and second mode resonant frequencies. Firstly, characteristics of each loop antenna fed by a microstrip transmission line (MSL) are simulated and measured to investigate fundamental radiation characteristics of these antennas. Next, a 16-element linear array antenna is simulated and measured. It is shown that the proposed antenna is suitable for the mobile satellite communications antenna.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"103 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":"129032171","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.2010.5650514
X. Fang, K. Leung, R. Chen
A compact wideband circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) with an underlaid 90° couplers is presented. The HEM11Δ (1< Δ <1) and HEM11Δ (1< Δ <2) modes of the cylindrical DRA are utilized to design the wideband CP DRA. The underlaid coupler is used to generate two quadrature signals, which are fed to two vertical excitation strips stuck on the side wall of the DRA. Since no extra footprint is needed for the coupler, the proposed antenna is very compact. With this compact configuration, loss of the feed network and, hence, reduction in the antenna gain, can be minimized. It was found that the 3dB axial-ratio bandwidth of the proposed antenna can be as wide as 22.5%. The reflection coefficient, radiation pattern, and antenna gain of the proposed antenna are studied, and reasonable agreement between the measured and simulated results is observed.
{"title":"Design of wideband circularly polarized cylindrical dielectric resonator antennas","authors":"X. Fang, K. Leung, R. Chen","doi":"10.1109/ICEAA.2010.5650514","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5650514","url":null,"abstract":"A compact wideband circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) with an underlaid 90° couplers is presented. The HEM11Δ (1< Δ <1) and HEM11Δ (1< Δ <2) modes of the cylindrical DRA are utilized to design the wideband CP DRA. The underlaid coupler is used to generate two quadrature signals, which are fed to two vertical excitation strips stuck on the side wall of the DRA. Since no extra footprint is needed for the coupler, the proposed antenna is very compact. With this compact configuration, loss of the feed network and, hence, reduction in the antenna gain, can be minimized. It was found that the 3dB axial-ratio bandwidth of the proposed antenna can be as wide as 22.5%. The reflection coefficient, radiation pattern, and antenna gain of the proposed antenna are studied, and reasonable agreement between the measured and simulated results is observed.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"16 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":"122836505","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.2010.5652936
J. Vrbancich
A helicopter time-domain airborne electromagnetic (AEM) system is under development for investigating the use of AEM for bathymetric mapping. Bathymetry and sediment thickness is computed from 1D inversion of the EM response based on a crude two-layer model (seawater/sediment) overlying resistive basement. The primary focus of this study is to test the accuracy of AEM for bathymetric mapping. A secondary objective is to map sediment thickness by determining the depth to bedrock. The AEM method senses the upper geo-electrical layers of the marine environment and is not sensitive to water turbidity and surf zone conditions because the optical opacity and presence of bubbles does not significantly affect the bulk electrical conductivity of seawater. The survey areas contain shallow waters (< 25 m) overlying paleovalleys infilled with unconsolidated sediment, and reef areas. Water depth accuracy of 1–2 m was achieved in water shallower than 25 m. This study shows that the AEM method is suited as a reconnaissance technique for rapid bathymetric mapping in turbid and surf-zone waters.
{"title":"Airborne electromagnetic sensing of shallow seawater using a helicopter time-domain system — Applications for bathymetric mapping and characterizing the seafloor","authors":"J. Vrbancich","doi":"10.1109/ICEAA.2010.5652936","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5652936","url":null,"abstract":"A helicopter time-domain airborne electromagnetic (AEM) system is under development for investigating the use of AEM for bathymetric mapping. Bathymetry and sediment thickness is computed from 1D inversion of the EM response based on a crude two-layer model (seawater/sediment) overlying resistive basement. The primary focus of this study is to test the accuracy of AEM for bathymetric mapping. A secondary objective is to map sediment thickness by determining the depth to bedrock. The AEM method senses the upper geo-electrical layers of the marine environment and is not sensitive to water turbidity and surf zone conditions because the optical opacity and presence of bubbles does not significantly affect the bulk electrical conductivity of seawater. The survey areas contain shallow waters (< 25 m) overlying paleovalleys infilled with unconsolidated sediment, and reef areas. Water depth accuracy of 1–2 m was achieved in water shallower than 25 m. This study shows that the AEM method is suited as a reconnaissance technique for rapid bathymetric mapping in turbid and surf-zone waters.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"36 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":"115375430","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.2010.5651282
W. Chew, L. Jiang, H. Chao, A. Hesford, M. K. Li, Z. Qian, Y. Liu, Y. P. Chen, Z. H. Ma, L. Sun, M. Tong, C. Davis, W. Sha
This paper reviews various methods to solve multi-scale problems ranging from low-frequency methods to very high-frequency methods.
本文综述了解决多尺度问题的各种方法，从低频方法到甚高频方法。
{"title":"Review of multi-scale electromagnetic modeling","authors":"W. Chew, L. Jiang, H. Chao, A. Hesford, M. K. Li, Z. Qian, Y. Liu, Y. P. Chen, Z. H. Ma, L. Sun, M. Tong, C. Davis, W. Sha","doi":"10.1109/ICEAA.2010.5651282","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5651282","url":null,"abstract":"This paper reviews various methods to solve multi-scale problems ranging from low-frequency methods to very high-frequency methods.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"119 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":"132628277","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.2010.5652257
A. del Corte Valiente, O. G. Blanco, J. M. G. Pulido
Airport security focuses on providing a cost effective and efficient operation to deliver high-quality and secure service to customers. For this, different technologies are deployed. For example, primary radar is used to detect airplanes during flight approach. Cameras, surface radar, and triangulation systems are deployed for ground surveillance. The ultimate goal of these systems is to improve the efficiency and safety of airport operations. However, airport areas where aircraft are parked, loaded, refueled, and boarded, present a high risk due to the large number of vehicles, goods and people involved in the aircraft handling activity. We propose different algorithms to improve location accuracy of vehicles and goods in critical airport areas where GPS satellite and radar coverage does not provide adequate target localization resolution.
{"title":"Increasing airport security with the development of high accuracy location algorithms based on ray-tracing techniques over WLAN networks","authors":"A. del Corte Valiente, O. G. Blanco, J. M. G. Pulido","doi":"10.1109/ICEAA.2010.5652257","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5652257","url":null,"abstract":"Airport security focuses on providing a cost effective and efficient operation to deliver high-quality and secure service to customers. For this, different technologies are deployed. For example, primary radar is used to detect airplanes during flight approach. Cameras, surface radar, and triangulation systems are deployed for ground surveillance. The ultimate goal of these systems is to improve the efficiency and safety of airport operations. However, airport areas where aircraft are parked, loaded, refueled, and boarded, present a high risk due to the large number of vehicles, goods and people involved in the aircraft handling activity. We propose different algorithms to improve location accuracy of vehicles and goods in critical airport areas where GPS satellite and radar coverage does not provide adequate target localization resolution.","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":"131503915","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.2010.5653036
J. Morris, S. Anderson
The ability of microwave radar to detect and characterize obstacles below the sea surface is dependent on the extent to which perturbations of the surface geometry and dynamics resulting from either movement of the obstacle or disruption of waves and currents due to the presence of the obstacle can be discriminated from the natural state of the surface in the absence of such obstacles. In this paper we report recent results from a systematic investigation of the radar signatures of some classes of submerged obstacles and examine some of the practical issues which can arise in operational implementation of a sensing capability.
{"title":"Statistical polarimetric radar detection of submerged obstacles via perturbed flows on the ocean surface","authors":"J. Morris, S. Anderson","doi":"10.1109/ICEAA.2010.5653036","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5653036","url":null,"abstract":"The ability of microwave radar to detect and characterize obstacles below the sea surface is dependent on the extent to which perturbations of the surface geometry and dynamics resulting from either movement of the obstacle or disruption of waves and currents due to the presence of the obstacle can be discriminated from the natural state of the surface in the absence of such obstacles. In this paper we report recent results from a systematic investigation of the radar signatures of some classes of submerged obstacles and examine some of the practical issues which can arise in operational implementation of a sensing capability.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"46 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":"131137940","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.2010.5654018
A. Hellicar, T. Bird, S. Hanham
Two antenna designs for the five hundred meter Aperture Spherical Telescope (FAST) are presented: a circular stepped horn and a circular profiled horn. The optical configuration of FAST imposes requirements on the antenna design. These requirements are used in optimizing the horn designs. Simulated results for the horns performance are presented and the ability of the designs to achieve FAST's requirements is discussed.
{"title":"Wideband short horn design for a multibeam radiotelescope","authors":"A. Hellicar, T. Bird, S. Hanham","doi":"10.1109/ICEAA.2010.5654018","DOIUrl":"https://doi.org/10.1109/ICEAA.2010.5654018","url":null,"abstract":"Two antenna designs for the five hundred meter Aperture Spherical Telescope (FAST) are presented: a circular stepped horn and a circular profiled horn. The optical configuration of FAST imposes requirements on the antenna design. These requirements are used in optimizing the horn designs. Simulated results for the horns performance are presented and the ability of the designs to achieve FAST's requirements is discussed.","PeriodicalId":375707,"journal":{"name":"2010 International Conference on Electromagnetics in Advanced Applications","volume":"21 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":"126899012","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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