2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)最新文献

{"title":"Ultra-broadband absorption in metallic gratings at the ‘plasmonic Brewster angle’","authors":"C. Argyropoulos, A. Alú","doi":"10.1109/USNC-URSI-NRSM.2013.6524999","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6524999","url":null,"abstract":"Summary form only given. In this talk we review the recently proposed concept of `plasmonic Brewster angle' [A. Alù, et al., Phys. Rev. Lett. 106, 123902 (2011)] and apply it to the design of ultrabroadband absorbers for THz and infrared radiation. Particular emphasis will be given to these energy harvesting potentials and interesting directional thermal emission properties. We will demonstrate that it is possible to realize ultra-broadband funneling, concentration and absorption of the impinging radiation within a one-dimensional (1D) subwavelength plasmonic grating, which is followed by an elongated adiabatically tapered plasmonic waveguide which can absorb light over a broad wavelength range. This effect is achieved in an angular range near the Brewster funneling condition, in analogy to the well-known Brewster transmission for ordinary dielectric etalon interfaces. Compared to conventional Brewster transmission, the plasmonic grating provides more degrees of freedom in patterning the angular response and the addition of elongated plasmonic tapers may extend this mechanism to almost omnidirectional broadband absorption at THz, infrared (IR) and optical frequencies with several interesting potential applications. These concepts will be generalized to two-dimensional (2D) plasmonic screens and analytical, numerical and experimental results will be demonstrated.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125939061","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":"Interconnection of complex cavities analyzed by the Random Coupling Model","authors":"G. Gradoni, T. Antonsen, S. Anlage, E. Ott","doi":"10.1109/USNC-URSI-NRSM.2013.6525049","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525049","url":null,"abstract":"Today, the statistical analysis of complex electromagnetic cavities constitutes a very active field of research in electronics, electromagnetic compatibility, wireless communications, and, more broadly, statistical physics. The Random Coupling Model (RCM) provides a framework for predicting the statistics of scattering of radiation in complicated enclosures (S. Hemmady, IEEE T-EMC, 54-4, 2012). Starting from the rigorous solution of Maxwell's equations, the RCM makes use of results from wave chaos and random matrix theory (RMT) to model the mode spectrum of cavities whose geometry is complicated or unknown in detail. Such an approach should be relevant to mode-stirred reverberation chambers (RC).","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121836453","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":"Design optimization of bowtie nanoantenna for high-efficiency thermophotovoltaics","authors":"Sangjo Choi, K. Sarabandi","doi":"10.1063/1.4836915","DOIUrl":"https://doi.org/10.1063/1.4836915","url":null,"abstract":"Summary form only given. The field enhancement and a novel matching technique at the terminals of a bowtie nanoantenna are utilized for developing compact, highly efficient, and flexible thermophotovoltaic (TPV) cells. The bowtie antenna is designed for maximum power transfer to an infra-red band (1μm to 2.2μm) of a TPV cell using Indium Gallium Arsenide Antimonide (InGaAsSb). A nano-meter size block of InGaAsSb with a low bandgap energy of ~0.5eV is mounted at the terminal of the antenna. Such load presents a frequency dependent impedance with high resistance and capacitance at the desired frequency (180THz). For maximum power transform a high impedance bowtie antenna operating at the anti-resonance mode in conjunction with an inductive stub is designed. The inductive stub which is implemented by open-ended transmission line with a length of 140nm is used to compensate the high capacitance of the load. The plasmonic behavior of the metal that tends to reduce the antenna size is to some extent compensated with the extra length needed to achieve anti-resonance condition. The proposed nanoantenna loaded with InGaAsSb block shows a field enhancement of order of ~23.5 at its terminal making this design also suitable for development of very sensitive IR detectors.A novel array configuration of the bowtie nanoantennas is presented that allows for collection of DC currents through an almost arbitrary parallel or series configuration of TPV or IR cells without adversely affecting the IR performance of the individual antennas. In this scheme elements can be arranged to be polarization dependent or independent. It is shown that the performance such thin flexible array can supersede the performance TPV cells of thick bulk InGaAsSb having same area.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127586690","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":"The interaction of electromagnetic waves and three-dimensional nonisotropic (uniaxial) wire medium metamaterials based on a transport model","authors":"E. Forati, G. Hanson","doi":"10.1109/USNC-URSI-NRSM.2013.6525097","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525097","url":null,"abstract":"Summary form only given. The transport model for the wire medium is introduced in (IEEE Trans. on Antennas and Propagation, v. 60, pp. 4219-4239, Sep. 2012) and basically defines an equivalent diffusion parameter (D) and a conductivity (or permittivity) for an isotropic wire medium satisfying the drift diffusion equation Jcond(r, ω)=σ(ω)E(r, ω)-D(ω)∇ρcond(r, ω) in which, Jcond, E, and ρ are homogenized conduction current, electric field, and charge inside the wire medium, respectively. Using this model we have shown previously that scattering problem formulations become simpler and less computationally intensive compared to other real-space methods. The validity of this homogenization method was confirmed for the isotropic wire medium sphere and was compared to the ABC method and the full wave simulation results in previous presentations (URSI 2012 meetings at Boulder and Chicago).","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130720460","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":"Signal chain architectures for efficient ionospheric radar processing","authors":"P. Erickson, W. Rideout, F. Lind","doi":"10.1109/USNC-URSI-NRSM.2013.6525061","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525061","url":null,"abstract":"Summary form only given. Powerful remote sensing techniques have been developed over the last several decades by the radio science community for probing of the ionospheric plasma state using radio wave scattering combined with passive or active illuminators. The last three decades have seen huge advances in processing and analysis speed afforded by modern specialized and general purpose computing platforms. Accordingly, elements and architectures in a software radar framework have grown to encompass much of the infrastructure used in modern ionospheric sensing platforms. particularly in applications of RF capture, signal processing, and inverse analysis. The dominance of software in these platforms has endowed them with new attributes of greatly enhanced Bexibility and reconfigurability. If managed carefully, these qualities can be used for improved spatial and temporal resolution, while reducing instrumental effects and improving measurement fidelity. Furthermore, streamlined and maximally generic pattern implementations in the design and execution of overall signal processing Bows have the significant advantage of minimizing overhead burdens in implementing new techniques. Finally, these architectures allow for the design of more generic analysis suites which partially insulate the operational facility against RF hardware migrations made necessary by system upgrades and maintenance. We will discuss strategies and implementations for interconnection of key signal pattern elements in the construction of modern software radar signal chains for reliable ionospheric remote sensing. Our philosophy of design encourages clear separation of key boundaries in the signal processing Bow, and speeds coding and debugging by focusing efforts on the essential software radar patterns. It also provides pathways for automated configuration and execution of signal chains for systems with large numbers of RF sensing elements such as phased array configurations. Finally, the presentation will describe a specific implementation of these concepts for a general radar calibration signal chain for incoherent scatter radar platforms, currently under development at the Millstone Hill Geospace Facility.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116823809","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":"Resonances of a spherical antenna","authors":"S. Seshadri","doi":"10.1109/USNC-URSI-NRSM.2013.6525099","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525099","url":null,"abstract":"The base of the spherical antenna is excited by a voltage V . The base current I = V / Z_in and the radiative power PR are determined. Maximum value P_Rm of P_R corresponding to X in = 0 is obtained. The normalized value of the radiative power is found as P_RN = P_R / P_Rm = M_D²/ M_D² + N_D² . This expression is used to obtain the Q of the resonances. Finally the singular features of the dipole mode resonances of the spherical antenna are summarized.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133855415","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":"Radio frequency interference identification and mitigation in pulsar observations using machine learning techniques","authors":"M. McCarty, G. Doran, T. Lazio, D. Thompson, J. Ford, R. Prestage","doi":"10.1109/USNC-URSI-NRSM.2013.6524993","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6524993","url":null,"abstract":"Summary form only given. Pulsar observations with the Robert C. Byrd Green Bank Telescope (GBT), located in Green Bank, WV, aid researchers in understanding the basic building blocks of our existence - matter, energy, space, and time - and how they behave under extreme physical conditions. Pulsars, rapidly rotating neutron stars with clock-like timing precision, can provide insights into a rich variety of physics and astrophysics.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"210 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133893208","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":"Performance of an L-Band antenna for radiometric measurements","authors":"M. Ogut, R. Lang, W. Wasylkiwskyj, M. Kurum, P. O’neill","doi":"10.1109/USNC-URSI-NRSM.2013.6525011","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525011","url":null,"abstract":"The objective of this paper is to discuss the performance of a new L-Band, truck-mounted radiometer antenna. This new low loss antenna has been designed to increase the calibration stability of the ComRAD radiometer system. ComRAD is a dual polarized combined radar radiometer system operating as a radar at 1.3 GHz and as a radiometer at 1.413 GHz. It utilizes the same antenna for both frequencies. ComRAD is used to develop algorithms for the sensing of soil moisture in the presence of vegetation. The system is presently being employed to monitor agricultural crops over the growing cycle in preparation for the upcoming SMAP (Soil Moisture Active Passive) satellite mission.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"227 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121041146","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":"Device characterization with non-contact probes in the THz band","authors":"C. Caglayan, G. Trichopoulos, K. Sertel","doi":"10.1109/USNC-URSI-NRSM.2013.6525079","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525079","url":null,"abstract":"Summary form only given. Advances in high-speed electronic devices enabled by new electronic materials and advanced processing techniques are opening up the THz band for integrated solutions in sensing, imaging, and communications. For example, InP-integrated circuits (mixers, LNAs, oscillators, etc.) have recently been demonstrated at 0.67 THz (Deal et al, IEEE Microwave and Wireless Component Letters, 21, 7, 368-370, 2011) and GaN is being considered to realize high power THz amplifiers and sources. Moreover, to circumvent the shortcomings of available devices, unconventional device topologies are being investigated (Dyakonov and Shur, Phys. Rev. Lett. 71, 15, 2465-2468, 1993; Zhang et al. IEEE Microwave and Wireless Component Letters, 21, 5, 267-269, 2011; Lederer et al. Solid State Electronics, 49, 9, 1488-1496, 2005). Nonetheless, testing and verification of the new devices at their intended operation frequencies has been a challenge (Reck et al, IEEE Trans. on Terahertz Science and Technology, 1, 2, 357-363, 2011). Particularly for frequencies above 500GHz, conventional contact probes are either not available, or extremely fragile for continuous use.To address the aforementioned difficulties in THz-frequency device testing, we have been developing a non-contact measurement approach that avoids the requirement to make physical contact with the test chip. Our approach is based on radiative coupling of network analyzer ports into the electromagnetic environment of the device (input and output co-planar waveguides) using integrated planar THz antennas (Topalli et al, 2012 IEEE Int. Symp. on Antennas and Propagation). Broadband butterfly-shaped antennas are used to ensure that the characterization setup is not limited by the bandwidth of the non-contact probe setup. As a first step in realizing these new probes, we recently fabricated test antennas and calibration structures (shorted CPW lines with varying lengths) on a 400um-thick GaAs wafer. The input impedance of the THz antennas were characterized in the 325-500GHz using contact probes (SP-I500-GSG-50-01) from Cascade Inc. and the implementation of the non-contact THz probe is under way. We will present the characterization details and our progress toward realizing this new THz frequency device testing methodology.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121181463","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":"Investigation of Stimulated Electromagnetic Emission SEE during second electron gyro-harmonic heating","authors":"A. Samimi, W. Scales, H. Fu, P. Bernhardt, S. Briczinski, M. McCarrick","doi":"10.1109/USNC-URSI-NRSM.2013.6525137","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525137","url":null,"abstract":"Features in the Stimulated Electromagnetic Emission (SEE) spectrum during heating near the second electron gyro-harmonic frequency have recently attracted significant attention due to their possible connection to artificial airglow and artificially generated ionization layers. Experimentally, three new phenomenologically related spectral features within 1 kHz of the heater frequency have been recently discovered: (1) discrete narrowband spectral structures ordered by ion gyro-frequency, (2) broadband features with power spectral density maximum near 500 Hz and (3) the broadband features with embedded ion gyro-harmonic structures.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121409196","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}