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

{"title":"Microwave receiver prototype development for the Hyperspectral Microwave Atmospheric Sounder (HyMAS)1","authors":"W. Blackwell, C. Galbraith, T. Hancock, R. Leslie, I. Osaretin, M. Shields, E. Thompson, P. Racette, L. Hilliard","doi":"10.1109/USNC-URSI-NRSM.2013.6525054","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525054","url":null,"abstract":"Recent technology advances have significantly changed the landscape of modern radiometry by enabling miniaturized, low-power, and low-noise radio-frequency receivers operating at frequencies up to 200 GHz. These advances enable the practical use of receiver arrays to multiplex multiple broad frequency bands into many spectral channels. We use the term “hyperspectral microwave” to refer generically to microwave sounding systems with approximately 50 spectral channels or more. We present the design and analysis of the receiver subsystem for the Hyperspectral Microwave Atmospheric Sounder (HyMAS), with focus on the ultra compact Intermediate Frequency (IF) processor module. HyMAS comprises multiple receivers operating near the oxygen absorption line at 118.75GHz and the water vapor absorption line at 183.31GHz. The hyperspectral microwave receiver system will be integrated into a scanhead compatible with the NASA GSFC Conical Scanning Microwave Imaging Radiometer (CoSMIR) airborne system to facilitate demonstration and performance characterization. HyMAS is designed to have a 52-channel hyperspectral microwave receiver subsystem with four temperature sounding bands (two antennas) near 118.75GHz and two moisture sounding bands (one antenna) near 183.31GHz. Both polarizations are measured (although at slightly different IF passbands) to increase the total channel count. Subharmonic mixers will be pumped by phase-locked oscillators, and single-sideband operation will be achieved by waveguide filtering of the lower sideband. Size/volume constraints on the receiver subsystem led to a relatively high IF frequency (18 - 29GHz) to facilitate miniaturization of the IF processor module. Broadband operation over such a relatively high intermediate frequency range is a technical challenge for the front-end receiver sys","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"251 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":"133696470","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":"SpectrumWiki: A framework for a crowd-sourced repository of information on spectrum usage","authors":"A. Clegg","doi":"10.1109/USNC-URSI-NRSM.2013.6524987","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6524987","url":null,"abstract":"Summary form only given. The radio spectrum is used for an enormous number and variety of applications. Some are common and well-known (e.g., cell phones & TV broadcast), some are highly specialized (e.g., ionosondes & LoJack), and still others are of historic interest only (e.g., CONELRAD & Omega). As radio spectrum becomes more valuable and crowded, interest has grown in knowing who uses what bands for what purposes.To this end, a specialized wiki has been created to serve as a crowd-sourced repository of information on spectrum use. A wiki is very much like an electronic encyclopedia where all users have “edit authority” to improve and update the contents at any time. Perhaps the best-known example is Wikipedia. SpectrumWiki has implemented a specialized framework to optimize the concept of a wiki for cataloging radio spectrum use. Essentially, all SpectrumWiki data and searches are keyed to frequency. Information on specific systems and applications can be entered, including the bands and services in which they operate. To query data, a frequency is entered and all systems and applications that use that frequency are returned in the search results. Additional features include the ability to upload documents, images, links, and other materials, and key them to specific bands and services. They will then be returned when the relevant bands are queried. This capability is especially useful for band plans, occupancy measurements, and legislation, and for tracking regulatory proceedings that impact specific bands/services. Expanded search capabilities are being developed that will allow, for example, the quick identification of all FCC documents that impact the radio astronomy service within the range 30-60 GHz for which the comment deadline is approaching within the next two weeks. At present, the basic wiki framework has been implemented, and a limited amount of data has been entered as a part of the development process. The site remains under continuous development and improvement, but data entry and queries, and suggestions for future features and bug fixes, are welcome. As with all wikis, the ultimate utility comes about when a significant number of users each enter a small amount of information in one or more areas in which they have specific knowledge. Anyone with an interest and/or expertise in radio spectrum use is encouraged to participate. The site is free and publicly accessible.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"8 36","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114087995","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":"Wraparound S-band and GPS antenna arrays for sounding rocket sub-payload","authors":"M. Maimaiti, R. Baktur","doi":"10.1109/USNC-URSI-NRSM.2013.6525034","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525034","url":null,"abstract":"The objective of this study is to determine a reliable and relatively simple antenna solution for a sounding rocket sub-payload. The sub-payload is a cylinder with a diameter of 6 inches and a height of 4 inches. The communication system requires S band and GPS antennas. In order to enable the payload to spin stably after launching, it is desirable to have both antennas conformal to the payload surface. Both antennas are required to provide a smooth omni-directional pattern, and therefore creating challenges as one needs multiple antennas to achieve the requirement on the limited payload surface area. Another challenge is to create a reliable circular polarized antenna that will be used as GPS antenna on the cylindrical surface.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"5 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":"114239242","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":"Synthesis of high-Q linear photonic crystal microcavities based on a real-k band structure solver","authors":"C. Poulton, Xiaoge Zeng, M. Popović","doi":"10.1109/USNC-URSI-NRSM.2013.6525090","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525090","url":null,"abstract":"Summary form only given. We present a rigorous and fast method for the design of linear photonic crystal (PhC) microcavities with high radiation quality factor (Q) and small modal volume (V) based on 3D, real-k band structure solver simulations. We further build on previous literature by studying critical design parameters including resonant wavelength walkoff, and resonant mode field distribution and its real and k-space engineering. Our approach treats equally efficiently various geometries of periodic structure including holes, slots, or other deformations in the linear waveguide. We compare a number of periodic structure designs, including the inclusion of reflectors such as circular holes and full width slots in a dielectric waveguide to form the cavities.The design method includes defining a unit cell of the crystal and tapering a single degree of freedom. Any parameters of the cavity (hole radius, slot width, guide width, etc.) can depend on this degree of freedom. The conduction (air) and valence (dielectric) bands of the unit cell are calculated at the Brillouin zone edge (k = π/a), where a is the periodicity of the unit cell and k is the crystal lattice vector, for a range of values of the degree of freedom. This yields the mirror strength as a function of the tapered degree of freedom for a target cavity resonance frequency. By fitting the mirror strength data to a polynomial function, a high-Q cavity can be designed by synthesizing a mirror strength distribution corresponding to a field distribution (e.g. Gaussian) with low radiation loss. Quality factors up to Q = 1010 are seen with a mode volume of V = 1.1(λ/n)3. The effects on both Q and mode volume are analyzed for different linear tapers. The difference of the target resonance frequency and the actual cavity resonance frequency is also assessed. A number of unit cell geometries are examined and the relationship between the magnitude of the band-gap between the conduction (air) and valence (dielectric) band and Q is examined. This design approach has been used to design PhC resonators for fabrication in standard silicon photonics as well as advanced CMOS electronics-photonics integration.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"10 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":"125249373","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":"Compensation networks to improve performance of Non-Foster circuits","authors":"A. Elfrgani, R. Rojas","doi":"10.1109/USNC-URSI-NRSM.2013.6525055","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525055","url":null,"abstract":"Non-Foster circuits (NFC) can be implemented with negative impedance converters (NIC) and/or Inverters (NII). This class of active circuits can violate Foster's Reactance Theorem, which is applicable to passive lossless circuits, and produce a reactance that has a negative slope with frequency. NFC are usually implemented with active transistor-based circuits. Non-Foster impedance circuit components can be very attractive for microwave and antenna applications since they are not restricted by the gain-bandwidth product. However, there are many issues involved in the design of these circuits, including stability, losses, linearity, and achieving higher operating frequencies into the gigahertz range.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"2 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":"127708424","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":"High frequency vector sensor design and testing","authors":"G. S. Antonio, W. Lee, M. Parent","doi":"10.1109/USNC-URSI-NRSM.2013.6525037","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525037","url":null,"abstract":"A new antenna design that exploits the simultaneous measurement of the complete electric and magnetic vector fields (vector sensor) has been designed, built, and tested experimentally. The sensor is designed for use in the high-frequency band (3-30MHz). Special consideration for potential operation near the ground/earth is incorporated into the antenna design, yielding a symmetric response amongst the individual field sensing components. The vector sensor consists of three orthogonally oriented electrically short dipoles as well as three electrically small orthogonal loop elements. Appropriate active impedance matching circuits transform the individual field sensors to a nominal 50 ohms for connection to a multichannel receiver system. Experimental measurements indicate that to first order the sensing components are sufficiently decoupled in spite of their relatively close electrical spacing.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"1 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":"125798188","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":"Metamaterial-based slow wave structure for travelling wave tubes","authors":"N. Apaydin, P. Douris, K. Sertel, J. Volakis","doi":"10.1109/USNC-URSI-NRSM.2013.6524996","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6524996","url":null,"abstract":"The advent of strong relativistic electron beams has led to the development of high power microwave sources. These devices generate high peaks of microwave power by transferring the kinetic energy in the electron beam to electromagnetic waves guided within a slow wave structure (SWS). Among these devices, traveling-wave tubes (TWTs) and backward wave oscillators (BWOs) are based on this principle, referred to as Cerenkov radiation. Strong interest also exists in employing the Cerenkov Maser (microwave amplification via stimulated emission of radiation) as a TWT due to its simplicity and tunability. This TWT is lined with a dielectric coating to slow down the electromagnetic waves. However, as noted by Shiffler et al. (Shiffler et al., IEEE Trans. Plasma Sci., 2010), dielectrics become vulnerable to charging and surface breakdowns. A way to avoid charging is to employ purely metallic metamaterial-based slow wave structures that emulate the behavior of a dielectric liner.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"98 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":"126089762","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":"Multistatic polarimetric radar data modeling","authors":"T. Webster, M. Cheney, E. Mokole","doi":"10.1109/USNC-URSI-NRSM.2013.6525095","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525095","url":null,"abstract":"Multistatic and polarimetric radars are two active areas of research. Polarimetric radar systems collect more information about an environment than if a single polarization is used, despite the historically prohibitive cost of these systems. Similarly, multistatic systems have a number of theoretical advantages, including 1) the ability to transmit multiple waveforms from collocated or distributed antennas, thus enabling interrogation of larger areas of interest due to the geometry of the system and 2) the possibility of augmenting fielded systems with additional low-power passive components. The design of a multistatic system, however, requires many decisions regarding the number, geometry, and polarization of the transmitters and receivers, and the waveforms that will be transmitted from each transmitter. These decisions will depend on the environment and targets of interest.","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":"130871903","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":"GPU implementation of parallelized microwave tomography algorithm","authors":"M. Holman, S. Noghanian","doi":"10.1109/USNC-URSI-NRSM.2013.6525058","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525058","url":null,"abstract":"Microwave tomography (MWT) has good potential to be used for medical imaging, however, most of MWT algorithms rely on local optimization methods and need regularization to find the a solution to inverse scattering problems. By using global optimization method for optimization, the non-deterministic nature of the genetic algorithm allows the inverse solver to avoid local minima without the use of regularization methods such as Tikhonov regularization. By not relying on regularization assumptions, high contrast areas of the imaging target can be resolved, whereas regularizations assume smooth dielectric contrast gradients. Resolving areas of high permittivity contrast is necessary to detect small tumors, less than a millimeter in length, as required for effective treatment. Our goal is to implement a fast MWT algorithm based on Finite Difference Time Domain (FDTD) forward solver and global optimization methods. In this regards, we propose the use of graphics processing unit (GPU) for FDTD computation. We have developed a FDTD program using NVidia's CUDA C language. The GPU implemented FDTD simulation was tested to yield 100-fold speed increase from standard Central Processing Unit (CPU) FDTD simulations.","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"2013 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":"129672581","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":"Exact scattering for axial incidence on concave soft and hard paraboloids","authors":"P. Uslenghi","doi":"10.1109/USNC-URSI-NRSM.2013.6525096","DOIUrl":"https://doi.org/10.1109/USNC-URSI-NRSM.2013.6525096","url":null,"abstract":"A scalar plane wave propagates along the axis of a concave paraboloid of revolution. The space inside the paraboloid is filled with a linear, homogeneous and isotropic medium, and the analysis is conducted in the phasor domain with a time-dependence factor exp (+jωt) and a propagation constant k. The surface of the paraboloid is either soft (Dirichlet boundary condition) or hard (Neumann boundary condition).","PeriodicalId":123571,"journal":{"name":"2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)","volume":"142 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":"124277725","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}