C. Johnson, C. L. Wagner, Robert T. Rebich, Jeffery L. Young, D. Butherus
{"title":"Propagation of low frequency signals in oceanic environments; theory, simulation and experimentation","authors":"C. Johnson, C. L. Wagner, Robert T. Rebich, Jeffery L. Young, D. Butherus","doi":"10.1109/APS.2011.5997003","DOIUrl":"https://doi.org/10.1109/APS.2011.5997003","url":null,"abstract":"The excitation and propagation of extremely, super and ultra low frequency signals (ELF, SLF and ULF) in the range of 30 Hz to 3,000 Hz associated with ocean environments are of particular interest for applications dealing with deep-water communications or sub-surface emissions caused by power generation devices and lines. Due to the relatively long wave-lengths on the order of hundreds of meters or so in saltwater and the high-power nature of the sources, it is possible to detect these signals several kilometers from the source. In the current age in which sophisticated electromagnetic modeling tools have been developed for high frequency applications, the question has been asked whether these same tools can be applied to ELF, SLF and ULF applications (referred to as just ELF in subsequent discussions). In particular, we wish to ascertain the usefulness and robustness of the finite-difference, time-domain (FDTD) method, commercial codes (e.g. HFSS and Maxwell), and layered media modeling using Sommerfeld and quasi-electrostatic methods as applied to the ELF propagation problem. Each of these approaches has its strengths and weaknesses, as described in the ensuing sections.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"41 1","pages":"2395-2398"},"PeriodicalIF":0.0,"publicationDate":"2011-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78159171","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}
{"title":"Contoured-beam dual-reflectarray antenna for DBS application","authors":"C. Tienda, J. Encinar, M. Arrebola","doi":"10.1109/APS.2011.5996652","DOIUrl":"https://doi.org/10.1109/APS.2011.5996652","url":null,"abstract":"In this paper, a dual-reflectarray antenna is proposed to generate a contoured beam for a DBS European coverage. The antenna optics is based on a compact range dual-reflector antenna, which produces low crosspolar radiation. The phase distribution of the subreflectarray is defined to simulate an equivalent hyperbolic subreflector with negative eccentricity. The phase distribution on the main reflectarray surface is synthesized to shape the beam providing the required coverage.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"64 1","pages":"109-112"},"PeriodicalIF":0.0,"publicationDate":"2011-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80829624","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}
{"title":"A 6-m mesh reflector antenna for SMAP: Modeling the RF performance of a challenging Earth-orbiting instrument","authors":"P. Focardi, P. Brown, Y. Rahmat-Samii","doi":"10.1109/APS.2011.5997157","DOIUrl":"https://doi.org/10.1109/APS.2011.5997157","url":null,"abstract":"A complete and accurate RF model of the SMAP observatory has been presented in this paper. Extreme care has been used in modeling all the important parts of the spacecraft to provide reliable information about the performance of the instrument under various conditions. An ongoing work of RF model refinement based on the constant development of the spacecraft and instrument is also being carried on to keep the model up to date. Field of view studies have been performed and mechanical and thermal deformations are also being considered. Since radiation pattern measurements of the actual antenna are not planned, the development of this RF model represents a very important milestone for the mission.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"921 1","pages":"2987-2990"},"PeriodicalIF":0.0,"publicationDate":"2011-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77534129","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}
{"title":"On the effect of breast compression and measurement setup configuration in microwave tomography for breast cancer detection","authors":"A. Diaz-Bolado, P. Barrière, J. Laurin","doi":"10.1109/APS.2011.5996812","DOIUrl":"https://doi.org/10.1109/APS.2011.5996812","url":null,"abstract":"The effect of the measurement setup configuration for Microwave Tomography (MT) is analyzed through several simple examples. Synthetic measurements are generated using a method of moments code and the well-known MR-CSI method is used for the solution of the inverse problem for the 2D TM scalar case. The quality of the reconstructed images is compared for the different configurations analyzed. Two configurations based on breast compression are compared to a classical circular measurement setup. An improvement in the quality of the reconstructed objects is observed when a compression of the object is applied due to the close proximity of the receivers. The Singular Value Decomposition (SVD) of the radiation operator is also obtained for the different configurations and the results obtained from this analysis further support the superior reconstruction capabilities of the presented configurations based on a compression of the object.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"74 1","pages":"714-717"},"PeriodicalIF":0.0,"publicationDate":"2011-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74316781","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}
L. Gupta, D. Ruddock, M. T. Hall, F. Sadeghi, D. Peroulis
{"title":"Remotely powered wireless strain telemeter","authors":"L. Gupta, D. Ruddock, M. T. Hall, F. Sadeghi, D. Peroulis","doi":"10.1109/APS.2011.5996563","DOIUrl":"https://doi.org/10.1109/APS.2011.5996563","url":null,"abstract":"This paper presents a wirelessly powered strain telemeter for mechanical health monitoring applications. The telemter is integrated with a rectenna tuned at 2.4 GHz. The rectenna is comprised by a resonant printed dipole antenna, microstrip transmission line filters and commercially available high-frequency diodes. The experimental results demonstrate that the rectenna is able to deliver 8 mW of DC power to the wireless telemeter when illuminated by a 10-W Yagi transmitter with a gain of 15 dB placed at a distance of over 2.5 m.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"50 1","pages":"1437-1440"},"PeriodicalIF":0.0,"publicationDate":"2011-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75787274","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}
{"title":"Extraction of rf permeability of ferrite materials using direct measurement of inductors on ferrite cores","authors":"K. Naishadham","doi":"10.1109/APS.2011.5996861","DOIUrl":"https://doi.org/10.1109/APS.2011.5996861","url":null,"abstract":"Ferrite materials are widely used as chokes to minimize common-mode currents in antenna feeds, in the design of artificial magnetic conductors, and in the filtering of noise at radio frequencies (RF). Miniature inductors, consisting of a thinwire coil around a high-permeability soft ferrite core, find wide application in RF and microwave circuits. An understanding of the high-frequency parasitic and packaging effects, such as stray capacitance, magnetic losses, resonant characteristics, etc., useful in the design of these components, can be gained from an equivalent circuit characterization of the inductor. In this paper, we present a rigorous experimental method to fully characterize the frequency dependent RF behavior of ferrite inductors. The equivalent circuit parameters of the inductor, as well as the complex effective permeability of the core, are extracted in closed form from an accurate measurement of the RF impedance, without recourse to cumbersome optimization procedures.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"38 1","pages":"1863-1866"},"PeriodicalIF":0.0,"publicationDate":"2011-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74389624","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}
Z. Jiang, C. Scarborough, D. Werner, P. Werner, C. Rivero‐Baleine, C. Drake
{"title":"An Isotropic 8.5 MHz magneti meta-lens","authors":"Z. Jiang, C. Scarborough, D. Werner, P. Werner, C. Rivero‐Baleine, C. Drake","doi":"10.1109/APS.2011.5996487","DOIUrl":"https://doi.org/10.1109/APS.2011.5996487","url":null,"abstract":"In this paper, we propose an isotropic metamaterial lens (meta-lens) with an operational frequency of 8.5 MHz for imaging applications. The cubic unit cells, composed of inductor-and and capacitor-loaded split rings, are aligned in a periodic three-dimensional dimensional lattice. The meta-lens provides an effective isotropic permeability μeff = −1 at 8.5 MHz. The lens enhances the evanescent fields, producing strong magnetic fields and sharp subwavelength resolution at the image plane. Measurements of a fabricated meta-lens were found to match full-wave simulations.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"68 1","pages":"1151-1154"},"PeriodicalIF":0.0,"publicationDate":"2011-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74326907","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}
Jeeheung Kim, S. Yoon, E. Jung, Jae W. Lee, Taek-Kyung Lee, W.K. Lee
{"title":"Triangular-shaped stepped septum polarizer for satellite communication","authors":"Jeeheung Kim, S. Yoon, E. Jung, Jae W. Lee, Taek-Kyung Lee, W.K. Lee","doi":"10.1109/APS.2011.5996409","DOIUrl":"https://doi.org/10.1109/APS.2011.5996409","url":null,"abstract":"In this paper, modified triangular-shaped waveguide-typed septum polarizer has been suggested and verified by using commercially available software and carrying out the comparison with the conventional rectangular waveguide-typed polarizer. It is expected that the proposed structure shows the better electrical performances than the conventional one in terms of the smooth energy-transfer of TE10 and TE01-modes. The simulated result shows that the proposed structure accomplished axial ratio of less than 0.32dB, return losses of lower than −32dB, and isolation characteristics between −24dB and −35dB at the target frequency ranging from 8 to 8.4GHz.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"23 1","pages":"854-857"},"PeriodicalIF":0.0,"publicationDate":"2011-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78509197","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}
{"title":"THz wave generation via electron beam-wave interaction in cylinderical photonic crystal waveguide","authors":"A. I. Nashed, S. Chaudhuri, S. Safavi-Naeini","doi":"10.1109/APS.2011.5996992","DOIUrl":"https://doi.org/10.1109/APS.2011.5996992","url":null,"abstract":"Electron beam-wave interaction using FDTD and Lorentz force equation is used to analyze interaction between electron beam and propagation modes of a slow wave structure supported inside an air-core cylindrical waveguide. Based on this model a THz signal generator at frequency ≈ 400GHz is proposed.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"59 1","pages":"2354-2357"},"PeriodicalIF":0.0,"publicationDate":"2011-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76121974","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}
{"title":"Leaky fields from damaged shields","authors":"Brian Jones, C. Furse","doi":"10.1109/APS.2011.5996865","DOIUrl":"https://doi.org/10.1109/APS.2011.5996865","url":null,"abstract":"Initial simulations and lab measurements were presented in this paper regarding leaky fields from small holes. Computer simulations provided motivation that external fields could be sensed by a rudimentary coil sensor. Lab experiments provided initial data that these external signals are detectable. The work going forward will focus on quantifying the effect of shield damage size and shape to leaky fields, the strength of the fields as the coil moves away, and optimal coil sensor design.","PeriodicalId":6449,"journal":{"name":"2011 IEEE International Symposium on Antennas and Propagation (APSURSI)","volume":"57 1","pages":"1878-1881"},"PeriodicalIF":0.0,"publicationDate":"2011-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76132154","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}