Pub Date : 2016-04-10DOI: 10.1109/EUCAP.2016.7481399
D. Villiers
This paper presents a space mapping approach to parametric modeling of the gain and sidelobe level in blocked aperture reflector antenna systems. The well-known aperture field integration method is used to provide a fast coarse model of the main beam responses, while full wave or multi-reflection physical optics simulations provide the accurate fine model responses. A formal implicit space mapping formulation is used to align the coarse and fine models over some low dimensional parameter space describing variations in the reflector geometry. The method is validated through two illustrative examples, showing significantly improved accuracy over the classical aperture integration method while requiring only a few full simulations of the structure.
{"title":"Accurate parametric modeling of gain and sidelobe levels in blocked aperture reflector systems using implicit space mapping","authors":"D. Villiers","doi":"10.1109/EUCAP.2016.7481399","DOIUrl":"https://doi.org/10.1109/EUCAP.2016.7481399","url":null,"abstract":"This paper presents a space mapping approach to parametric modeling of the gain and sidelobe level in blocked aperture reflector antenna systems. The well-known aperture field integration method is used to provide a fast coarse model of the main beam responses, while full wave or multi-reflection physical optics simulations provide the accurate fine model responses. A formal implicit space mapping formulation is used to align the coarse and fine models over some low dimensional parameter space describing variations in the reflector geometry. The method is validated through two illustrative examples, showing significantly improved accuracy over the classical aperture integration method while requiring only a few full simulations of the structure.","PeriodicalId":89840,"journal":{"name":"Proceedings of the European Conference on Antennas and Propagation. European Conference on Antennas and Propagation","volume":"1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89886478","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 : 2016-04-10DOI: 10.1109/EUCAP.2016.7481728
E. Lil, Jan-Willem De Bleser
The low frequency instability in the method of moments becomes important when objects smaller than the wavelength have to be computed. For a PEC (Perfectly Electrically Conducting) body, this leads to uncoupling or splitting the integral equations by using first the MFIE (Magnetic Field Integral Equation) for the currents and consecutively the EFIE (Electric Field Integral Equation) for the charges. For dielectric bodies, the charge is reintroduced. The contribution of this paper consists in implementing an efficient technique, reducing the computational complexity, in time but mostly in memory. A toolkit has been developed to perform accurate computations. The technique has been verified quantitatively, checking the charge and current distributions against analytic solutions where existing, as well as qualitatively against the boundary conditions for the scattered field. Many examples will be given, both in frequency and in time domain (obtained by inverting frequency domain calculations including the DC (Direct Current) component).
{"title":"STEMO, a stabilized toolkit for embedded dielectric structures with moment methods","authors":"E. Lil, Jan-Willem De Bleser","doi":"10.1109/EUCAP.2016.7481728","DOIUrl":"https://doi.org/10.1109/EUCAP.2016.7481728","url":null,"abstract":"The low frequency instability in the method of moments becomes important when objects smaller than the wavelength have to be computed. For a PEC (Perfectly Electrically Conducting) body, this leads to uncoupling or splitting the integral equations by using first the MFIE (Magnetic Field Integral Equation) for the currents and consecutively the EFIE (Electric Field Integral Equation) for the charges. For dielectric bodies, the charge is reintroduced. The contribution of this paper consists in implementing an efficient technique, reducing the computational complexity, in time but mostly in memory. A toolkit has been developed to perform accurate computations. The technique has been verified quantitatively, checking the charge and current distributions against analytic solutions where existing, as well as qualitatively against the boundary conditions for the scattered field. Many examples will be given, both in frequency and in time domain (obtained by inverting frequency domain calculations including the DC (Direct Current) component).","PeriodicalId":89840,"journal":{"name":"Proceedings of the European Conference on Antennas and Propagation. European Conference on Antennas and Propagation","volume":"1 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2016-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79607842","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 : 2014-04-06DOI: 10.1109/EUCAP.2014.6901675
R. V. Nee
Wireless LAN has come a long way since its inception in the early nineties. After a decade of proprietary products, wireless LAN suddenly became a mass market with the adoption of the 802.11b standard and the formation of WiFi. Since then there has been a continuous stream of innovations in products and standards. The main emphasis thus far has been on peak throughput for a single link, leading to the use of higher bandwidth, higher constellation size, and MIMO. As the available spectrum fills up though, the emphasis will gradually shift towards a high overall capacity. This means the focus will be less on larger bandwidth or constellation size and more on using more antennas with MIMO or Multi-User MIMO. In addition to addressing all these issues, this talk will show some MIMO propagation characteristics of typical indoor wireless channels and try to predict where WiFi is going.
{"title":"Wireless LAN — Quo Vadis?","authors":"R. V. Nee","doi":"10.1109/EUCAP.2014.6901675","DOIUrl":"https://doi.org/10.1109/EUCAP.2014.6901675","url":null,"abstract":"Wireless LAN has come a long way since its inception in the early nineties. After a decade of proprietary products, wireless LAN suddenly became a mass market with the adoption of the 802.11b standard and the formation of WiFi. Since then there has been a continuous stream of innovations in products and standards. The main emphasis thus far has been on peak throughput for a single link, leading to the use of higher bandwidth, higher constellation size, and MIMO. As the available spectrum fills up though, the emphasis will gradually shift towards a high overall capacity. This means the focus will be less on larger bandwidth or constellation size and more on using more antennas with MIMO or Multi-User MIMO. In addition to addressing all these issues, this talk will show some MIMO propagation characteristics of typical indoor wireless channels and try to predict where WiFi is going.","PeriodicalId":89840,"journal":{"name":"Proceedings of the European Conference on Antennas and Propagation. European Conference on Antennas and Propagation","volume":"2 1","pages":"2-2"},"PeriodicalIF":0.0,"publicationDate":"2014-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88247061","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 : 2014-04-06DOI: 10.1109/EUCAP.2014.6901981
E. Lil, Jan-Willem De Bleser
In some cases the objects like wind turbines are so large that the far-field condition are not met within the visibility of the object due to the curvature of the earth. Therefor, new ways to compute the reflections of those objects are required. This is similar to the concept of near-field communications, where the far-field gain (the normal definition) has to be replaced by the near-field gain. In some cases, we will even be able to find simple formulas for the worst case RCS in function of the relative size of the object with respect to the wavelength.
{"title":"On the efficient computation of near-field radar cross sections","authors":"E. Lil, Jan-Willem De Bleser","doi":"10.1109/EUCAP.2014.6901981","DOIUrl":"https://doi.org/10.1109/EUCAP.2014.6901981","url":null,"abstract":"In some cases the objects like wind turbines are so large that the far-field condition are not met within the visibility of the object due to the curvature of the earth. Therefor, new ways to compute the reflections of those objects are required. This is similar to the concept of near-field communications, where the far-field gain (the normal definition) has to be replaced by the near-field gain. In some cases, we will even be able to find simple formulas for the worst case RCS in function of the relative size of the object with respect to the wavelength.","PeriodicalId":89840,"journal":{"name":"Proceedings of the European Conference on Antennas and Propagation. European Conference on Antennas and Propagation","volume":"1 1","pages":"1174-1177"},"PeriodicalIF":0.0,"publicationDate":"2014-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87113630","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}
This presentation provides an overview of electromagnetic heating technology that has proven useful in clinical applications of hyperthermia therapy for cancer. Several RF and microwave antenna designs are illustrated which highlight the evolution of technology from simple waveguide antennas to spatially and temporally adjustable multiple antenna phased arrays for deep heating, conformal arrays for superficial heating, and compatible approaches for radiometric and magnetic resonance image based non-invasive thermal monitoring. Examples of heating capabilities for several recently developed applicators demonstrate highly adjustable power deposition that has not been possible in the past.
{"title":"EVOLUTION OF ANTENNA PERFORMANCE FOR APPLICATIONS IN THERMAL MEDICNE.","authors":"P R Stauffer, P F Maccarini","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>This presentation provides an overview of electromagnetic heating technology that has proven useful in clinical applications of hyperthermia therapy for cancer. Several RF and microwave antenna designs are illustrated which highlight the evolution of technology from simple waveguide antennas to spatially and temporally adjustable multiple antenna phased arrays for deep heating, conformal arrays for superficial heating, and compatible approaches for radiometric and magnetic resonance image based non-invasive thermal monitoring. Examples of heating capabilities for several recently developed applicators demonstrate highly adjustable power deposition that has not been possible in the past.</p>","PeriodicalId":89840,"journal":{"name":"Proceedings of the European Conference on Antennas and Propagation. European Conference on Antennas and Propagation","volume":" ","pages":"3080-3083"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3593730/pdf/nihms391794.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31304666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The geometry of a planar array of parasitic dipoles is optimized to modify the pattern of an active dipole above a ground plane, in order to obtain a pencil beam of moderate gain and bandwidth without requiring a complex feeding network. As an example of application, a pencil beam pattern radiated by a planar array of parasitic dipoles fed by only one active dipole at 1.645 GHz is shown.
{"title":"Pencil beam patterns obtained by a planar array of parasitic dipoles fed by only one active element","authors":"M. A. Folgueiras, J. A. R. Gonzalez, F. Pena","doi":"10.2528/PIER10040705","DOIUrl":"https://doi.org/10.2528/PIER10040705","url":null,"abstract":"The geometry of a planar array of parasitic dipoles is optimized to modify the pattern of an active dipole above a ground plane, in order to obtain a pencil beam of moderate gain and bandwidth without requiring a complex feeding network. As an example of application, a pencil beam pattern radiated by a planar array of parasitic dipoles fed by only one active dipole at 1.645 GHz is shown.","PeriodicalId":89840,"journal":{"name":"Proceedings of the European Conference on Antennas and Propagation. European Conference on Antennas and Propagation","volume":"31 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2010-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81399846","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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