Sailing He, Yiming Zhang, Laijun Li, Yuefeng Lu, Y. Zhang, Hui Liu
It is challenging to design a high-performance UHF RFID tag antenna on a liquid-filled bottle due to the high conductivity, high permittivity, and the variety of liquids. A systematic way how to design a high-performance UHF RFID tag antenna on a liquid-filled bottle is presented. A simple design consisting of a folded dipole and a loop matching structure is first proposed for a tag antenna placed on a water bottle. A co-design approach is adopted to make the water and bottle surface become a part of the tag antenna to eliminate the significant influence of the environment. The measurement results at 915 MHz show that the reading range of the simple design can reach 8 m in the absence of the water bottle and reach 4.2 m when it is placed on a water bottle. The folded dipole on the water bottle is then optimized to improve the gain significantly, and a maximum gain of −5.54 dBi is achieved at 915 MHz. Furthermore, the impedance bandwidth for the tag antenna on the water bottle is greatly improved by increasing the number of loops in the impedance matching structure from one to three, and the −6 dB impedance bandwidth of over 100 MHz (simulation) or 84 MHz (experiment) is achieved. A reading range of 5.6 m is achieved when the tag antenna is placed on a water bottle at 915 MHz.
{"title":"HIGH PERFORMANCE UHF RFID TAG ANTENNAS ON LIQUID-FILLED BOTTLES","authors":"Sailing He, Yiming Zhang, Laijun Li, Yuefeng Lu, Y. Zhang, Hui Liu","doi":"10.2528/PIER19041001","DOIUrl":"https://doi.org/10.2528/PIER19041001","url":null,"abstract":"It is challenging to design a high-performance UHF RFID tag antenna on a liquid-filled bottle due to the high conductivity, high permittivity, and the variety of liquids. A systematic way how to design a high-performance UHF RFID tag antenna on a liquid-filled bottle is presented. A simple design consisting of a folded dipole and a loop matching structure is first proposed for a tag antenna placed on a water bottle. A co-design approach is adopted to make the water and bottle surface become a part of the tag antenna to eliminate the significant influence of the environment. The measurement results at 915 MHz show that the reading range of the simple design can reach 8 m in the absence of the water bottle and reach 4.2 m when it is placed on a water bottle. The folded dipole on the water bottle is then optimized to improve the gain significantly, and a maximum gain of −5.54 dBi is achieved at 915 MHz. Furthermore, the impedance bandwidth for the tag antenna on the water bottle is greatly improved by increasing the number of loops in the impedance matching structure from one to three, and the −6 dB impedance bandwidth of over 100 MHz (simulation) or 84 MHz (experiment) is achieved. A reading range of 5.6 m is achieved when the tag antenna is placed on a water bottle at 915 MHz.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84556059","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}
The ideal ultra-wideband (UWB) antenna feed for lens and reflector systems radiates a uniform and customizable beamwidth vs. frequency. Here, a new antenna concept for radiating frequency-independent Gaussian beams with arbitrary bandwidths and beamwidths is reported. It is analytically shown how to resistively load a transmission line network to maintain a Gaussian amplitude taper across an antenna array aperture. In contrast to many other feed antennas, the radiation properties here can be tailored without time-consuming full wave optimizations. The radiated beamwidth, bandwidth, antenna size, radiation efficiency, and gain can all be quickly estimated using the derived closed-form expressions. An example, 16 × 16 Vivaldi element array is fed with a network of resistively loaded microstrip lines. The simulated array radiates a Gaussian beam with 10 dB full beamwidth of 35◦ ± 5◦ and directivity of 20 dB ± 1.5 dB over 6.5GHz–19GHz (3 : 1 bandwidth ratio). However, the radiation efficiency is inherently low due to the large loss associated with generating the Gaussian amplitude taper at all frequencies. The example array has a simulated radiation efficiency of 1% at the higher operating frequencies. The array was fabricated and measured. The measured beamwidths agree well with simulation to validate the reported theory. This architecture is a particularly attractive option for feed antennas that require customizable directivities, and can tolerate low radiation efficiencies such as test and measurement.
{"title":"UNIFORM BEAMWIDTH UWB FEED ANTENNA USING LOSSY TRANSMISSION LINES","authors":"C. Pfeiffer, Thomas Steffen, G. Kakas","doi":"10.2528/pier19081202","DOIUrl":"https://doi.org/10.2528/pier19081202","url":null,"abstract":"The ideal ultra-wideband (UWB) antenna feed for lens and reflector systems radiates a uniform and customizable beamwidth vs. frequency. Here, a new antenna concept for radiating frequency-independent Gaussian beams with arbitrary bandwidths and beamwidths is reported. It is analytically shown how to resistively load a transmission line network to maintain a Gaussian amplitude taper across an antenna array aperture. In contrast to many other feed antennas, the radiation properties here can be tailored without time-consuming full wave optimizations. The radiated beamwidth, bandwidth, antenna size, radiation efficiency, and gain can all be quickly estimated using the derived closed-form expressions. An example, 16 × 16 Vivaldi element array is fed with a network of resistively loaded microstrip lines. The simulated array radiates a Gaussian beam with 10 dB full beamwidth of 35◦ ± 5◦ and directivity of 20 dB ± 1.5 dB over 6.5GHz–19GHz (3 : 1 bandwidth ratio). However, the radiation efficiency is inherently low due to the large loss associated with generating the Gaussian amplitude taper at all frequencies. The example array has a simulated radiation efficiency of 1% at the higher operating frequencies. The array was fabricated and measured. The measured beamwidths agree well with simulation to validate the reported theory. This architecture is a particularly attractive option for feed antennas that require customizable directivities, and can tolerate low radiation efficiencies such as test and measurement.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86946059","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}
Gaoxuan Wang, P. Kulinski, P. Hubert, A. Deguine, D. Petitprez, S. Crumeyrolle, E. Fertein, K. Deboudt, P. Flament, M. Sigrist, H. Yi, Weidong Chen
Accurate measurement of atmospheric particulate matter (PM) absorption coefficient is highly required for study of earth climate change and for monitoring of air quality. In addition, multiwavelength measurements of PM absorption can provide information on the PM chemical composition (black carbon or brown carbon). A multi-wavelengths photoacoustic (MW-PA) spectrophone operating at 444, 532 and 660 nm was developed and deployed for filter-free characterization of wavelengthdependent optical properties of PM mass absorption coefficient (MAC) and absorption Ångström coefficient (AAC). It is worth noting that to date no any AAC of volcanic ashes determined by filter-free measurement have been reported. The developed MW-PA spectrophone was deployed to an intensive field campaign measurement of environmental PM in Grenoble (France). Side-by-side inter-comparison measurements of ambient PM showed a good correlation between the developed MW-PA spectrophone and a reference instrument aethalometer (Magee scientific, AE33).
{"title":"FILTER-FREE LIGHT ABSORPTION MEASUREMENT OF VOLCANIC ASHES AND AMBIENT PARTICULATE MATTER USING MULTI-WAVELENGTH PHOTOACOUSTIC SPECTROSCOPY","authors":"Gaoxuan Wang, P. Kulinski, P. Hubert, A. Deguine, D. Petitprez, S. Crumeyrolle, E. Fertein, K. Deboudt, P. Flament, M. Sigrist, H. Yi, Weidong Chen","doi":"10.2528/pier19100603","DOIUrl":"https://doi.org/10.2528/pier19100603","url":null,"abstract":"Accurate measurement of atmospheric particulate matter (PM) absorption coefficient is highly required for study of earth climate change and for monitoring of air quality. In addition, multiwavelength measurements of PM absorption can provide information on the PM chemical composition (black carbon or brown carbon). A multi-wavelengths photoacoustic (MW-PA) spectrophone operating at 444, 532 and 660 nm was developed and deployed for filter-free characterization of wavelengthdependent optical properties of PM mass absorption coefficient (MAC) and absorption Ångström coefficient (AAC). It is worth noting that to date no any AAC of volcanic ashes determined by filter-free measurement have been reported. The developed MW-PA spectrophone was deployed to an intensive field campaign measurement of environmental PM in Grenoble (France). Side-by-side inter-comparison measurements of ambient PM showed a good correlation between the developed MW-PA spectrophone and a reference instrument aethalometer (Magee scientific, AE33).","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81871521","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 NUMERICAL KIRCHHOFF SIMULATOR FOR GNSS-R LAND APPLICATIONS","authors":"Weihui Gu, Haokui Xu, L. Tsang","doi":"10.2528/PIER18121803","DOIUrl":"https://doi.org/10.2528/PIER18121803","url":null,"abstract":"","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82153187","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}
The method of broadband Green's functions with low wavenumber extractions (BBGFL) is used to calculate Green's function for inhomogeneous waveguides filled with different dielectrics and with irregular boundaries. To construct the BBGFL modal solutions, we derive governing equations of the linear eigen-matrix problem and orthonormalization condition. In BBGFL, the Green's function is represented in modal expansions with convergence accelerated by higher order low wavenumber extractions. To obtain a linear eigenvalue problem for the modes, we use two BBGFLs of rectangular waveguides with two dielectric wavenumbers. The orthonormalized mode functions are used to construct the Green's function. Current wavenumber derivatives and Green's function wavenumber derivatives are computed by a single low wavenumber MoM impedance matrix. The wavenumber derivatives are used to accelerate the convergence of modal summations to 6th order. Numerical results are illustrated and compared with the direct MoM method of using free space Green's function. Results show accuracies and computation efficiencies for broadband simulations of Green's functions.
{"title":"BROADBAND GREEN’S FUNCTION WITH HIGHER ORDER LOW WAVENUMBER EXTRACTIONS FOR AN INHOMOGENEOUS WAVEGUIDE WITH IRREGULAR SHAPE","authors":"T. Liao, K. Ding, L. Tsang","doi":"10.2528/PIER18102903","DOIUrl":"https://doi.org/10.2528/PIER18102903","url":null,"abstract":"The method of broadband Green's functions with low wavenumber extractions (BBGFL) is used to calculate Green's function for inhomogeneous waveguides filled with different dielectrics and with irregular boundaries. To construct the BBGFL modal solutions, we derive governing equations of the linear eigen-matrix problem and orthonormalization condition. In BBGFL, the Green's function is represented in modal expansions with convergence accelerated by higher order low wavenumber extractions. To obtain a linear eigenvalue problem for the modes, we use two BBGFLs of rectangular waveguides with two dielectric wavenumbers. The orthonormalized mode functions are used to construct the Green's function. Current wavenumber derivatives and Green's function wavenumber derivatives are computed by a single low wavenumber MoM impedance matrix. The wavenumber derivatives are used to accelerate the convergence of modal summations to 6th order. Numerical results are illustrated and compared with the direct MoM method of using free space Green's function. Results show accuracies and computation efficiencies for broadband simulations of Green's functions.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91205947","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}
Samir Ouedraogo, Israel David Hinostroza Sáenz, R. Guinvarc’h, R. Gillard
A multifunction antenna system providing a radar function and a communication function simultaneously is proposed. The system is composed of a horn antenna whose feeding waveguide is loaded with slots. The horn radiation is used for the main radar function. The slotted waveguide radiation is controlled independently from the horn radiation to perform a direct binary phase shift keying (BPSK) communication provided that each radiating slot is equipped with a simple switching mechanism. Then, the antenna system provides two different functions using orthogonal polarizations and directions. Measured results show 9.1 dB and 32 dB isolation between the two functions at the working frequency. In addition, the proposed system can be integrated with the existing radars which use horns by replacing only the feeding waveguide.
{"title":"DESIGN AND EXPERIMENTAL VALIDATION OF MULTIFUNCTION ANTENNA WITH DIRECT MODULATION FOR RADAR AND COMMUNICATION","authors":"Samir Ouedraogo, Israel David Hinostroza Sáenz, R. Guinvarc’h, R. Gillard","doi":"10.2528/pier18061804","DOIUrl":"https://doi.org/10.2528/pier18061804","url":null,"abstract":"A multifunction antenna system providing a radar function and a communication function simultaneously is proposed. The system is composed of a horn antenna whose feeding waveguide is loaded with slots. The horn radiation is used for the main radar function. The slotted waveguide radiation is controlled independently from the horn radiation to perform a direct binary phase shift keying (BPSK) communication provided that each radiating slot is equipped with a simple switching mechanism. Then, the antenna system provides two different functions using orthogonal polarizations and directions. Measured results show 9.1 dB and 32 dB isolation between the two functions at the working frequency. In addition, the proposed system can be integrated with the existing radars which use horns by replacing only the feeding waveguide.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82843925","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}
Quantitative estimation of both conductivity and permittivity of biological tissues is essential in many biomedical applications, ranging from therapeutic treatments to safety assessment of medical devices and dosimetry. Typically, the electromagnetic field distribution inside the body is predicted based on available ex-vivo measured electrical properties. Unfortunately, these values may be quite different from the ones measured in-vivo and cannot account for the differences among individuals. As a result, their use can introduce significant errors affecting therapeutic treatments and dose estimation. To cope with this problem, in this paper a new approach for estimation of effective electrical properties of human tissues is introduced. The proposed strategy is based on the solution of an inverse scattering problem (by means of a contrast source inversion scheme) and the use of an effective representation of the unknowns based on spatial priors derived by magnetic resonance imaging or computed tomography. The approach is tested in controlled conditions against simulated single frequency data and realistic and anthropomorphic head and neck phantoms. Moreover, the inherent advantages have been assessed in the framework of hyperthermia treatment planning.
{"title":"A METHOD FOR EFFECTIVE PERMITTIVITY AND CONDUCTIVITY MAPPING OF BIOLOGICAL SCENARIOS VIA SEGMENTED CONTRAST SOURCE INVERSION","authors":"M. Bevacqua, G. Bellizzi, T. Isernia, L. Crocco","doi":"10.2528/PIER18071704","DOIUrl":"https://doi.org/10.2528/PIER18071704","url":null,"abstract":"Quantitative estimation of both conductivity and permittivity of biological tissues is essential in many biomedical applications, ranging from therapeutic treatments to safety assessment of medical devices and dosimetry. Typically, the electromagnetic field distribution inside the body is predicted based on available ex-vivo measured electrical properties. Unfortunately, these values may be quite different from the ones measured in-vivo and cannot account for the differences among individuals. As a result, their use can introduce significant errors affecting therapeutic treatments and dose estimation. To cope with this problem, in this paper a new approach for estimation of effective electrical properties of human tissues is introduced. The proposed strategy is based on the solution of an inverse scattering problem (by means of a contrast source inversion scheme) and the use of an effective representation of the unknowns based on spatial priors derived by magnetic resonance imaging or computed tomography. The approach is tested in controlled conditions against simulated single frequency data and realistic and anthropomorphic head and neck phantoms. Moreover, the inherent advantages have been assessed in the framework of hyperthermia treatment planning.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74339446","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}
Several computational imaging systems have recently been proposed at microwave and millimeter-wave frequencies enabling a fast and low cost reconstruction of the scattering strength of a scene. The quality of the reconstructed images is directly linked to the degrees of freedom of the system which are the number of uncorrelated radiated patterns that sequentially sample the scene. Frequency diverse antennas such as leaky chaotic cavities and metamaterial apertures take advantage of the spectral decorrelation of transmitted speckle patterns that stems from the reverberation within a medium. We present a reconfigurable chaotic cavity for which the boundary conditions can be tuned by exciting plasma elements, here commercial fluorescent lamps. The interaction of electromagnetic waves with a cold plasma is strongly modified as it is ionized. Instead of being transparent to incident waves, it behaves theoretically as a metallic material. The independent states of the cavity obtained using a differential approach further enhance the degrees of freedom. This relaxes the need of a cavity with a large bandwidth and/or high quality factor. Experimental results validate the use of fluorescent lamps and its limitations are discussed. Images of various metallic objects are provided to illustrate the potentialities of this promising solution.
{"title":"A RECONFIGURABLE CHAOTIC CAVITY WITH FLUORESCENT LAMPS FOR MICROWAVE COMPUTATIONAL IMAGING","authors":"Ariel Christopher Tondo Yoya, B. Fuchs, M. Davy","doi":"10.2528/PIER19011602","DOIUrl":"https://doi.org/10.2528/PIER19011602","url":null,"abstract":"Several computational imaging systems have recently been proposed at microwave and millimeter-wave frequencies enabling a fast and low cost reconstruction of the scattering strength of a scene. The quality of the reconstructed images is directly linked to the degrees of freedom of the system which are the number of uncorrelated radiated patterns that sequentially sample the scene. Frequency diverse antennas such as leaky chaotic cavities and metamaterial apertures take advantage of the spectral decorrelation of transmitted speckle patterns that stems from the reverberation within a medium. We present a reconfigurable chaotic cavity for which the boundary conditions can be tuned by exciting plasma elements, here commercial fluorescent lamps. The interaction of electromagnetic waves with a cold plasma is strongly modified as it is ionized. Instead of being transparent to incident waves, it behaves theoretically as a metallic material. The independent states of the cavity obtained using a differential approach further enhance the degrees of freedom. This relaxes the need of a cavity with a large bandwidth and/or high quality factor. Experimental results validate the use of fluorescent lamps and its limitations are discussed. Images of various metallic objects are provided to illustrate the potentialities of this promising solution.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"95 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73663248","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}
The spectral functions are studied in conjunction with the dyadic Green's functions for various media. The dyadic Green's functions are found using the eigenfunction expansion method for homogeneous, inhomogeneous, periodic, lossless, lossy, and anisotropic media, guided by the Bloch- Floquet theorem. For the lossless media cases, the spectral functions can be directly related to the photon local density of states, and hence, to the electromagnetic energy density. For the lossy case, the spectral function can be related to the field correlation function. Because of these properties, one can derive properties for field correlations and the Langevin-source correlations without resorting to the fluctuation dissipation theorem. The results are corroborated by the fluctuation dissipation theorem. An expression for the local density of states for lossy, inhomogeneous, and dispersive media has also been suggested.
{"title":"GREEN'S DYADIC, SPECTRAL FUNCTION, LOCAL DENSITY OF STATES, AND FLUCTUATION DISSIPATION THEOREM","authors":"W. Chew, W. Sha, Q. Dai","doi":"10.2528/pier19111801","DOIUrl":"https://doi.org/10.2528/pier19111801","url":null,"abstract":"The spectral functions are studied in conjunction with the dyadic Green's functions for various media. The dyadic Green's functions are found using the eigenfunction expansion method for homogeneous, inhomogeneous, periodic, lossless, lossy, and anisotropic media, guided by the Bloch- Floquet theorem. For the lossless media cases, the spectral functions can be directly related to the photon local density of states, and hence, to the electromagnetic energy density. For the lossy case, the spectral function can be related to the field correlation function. Because of these properties, one can derive properties for field correlations and the Langevin-source correlations without resorting to the fluctuation dissipation theorem. The results are corroborated by the fluctuation dissipation theorem. An expression for the local density of states for lossy, inhomogeneous, and dispersive media has also been suggested.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74412802","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}
The di-culty of focusing high-resolution highly squinted SAR data comes from the serious azimuth-range coupling, which needs to be compensated in the procedure of imaging. Generally, the linear range walk correction (LRWC) can reduce the coupling efiectively, however, it also induces the problem of azimuth-dependence of residual range cell migration (RCM) and quadratic phase. A novel algorithm is proposed to solve this problem in this paper. In this algorithm, the azimuth nonlinear chirp scaling (ANCS) operation is used, which can not only eliminate the azimuth space variation of residual RCM and frequency modulation (FM) rate but also remove the azimuth misregistration. In addition, the range chirp scaling operation is applied to correct the range-dependent RCM. After implementing the unifled RCM correction, range compression and azimuth compression sequentially, the focused SAR image is acquired flnally. The experimental results with simulated data demonstrate that the proposed algorithm outperforms the existing algorithms.
{"title":"AZIMUTH NONLINEAR CHIRP SCALING INTEGRATED WITH RANGE CHIRP SCALING ALGORITHM FOR HIGHLY SQUINTED SAR IMAGING","authors":"Qinglin Zhai, Wei Wang, Jiemin Hu, Jun Zhang","doi":"10.2528/PIER13080608","DOIUrl":"https://doi.org/10.2528/PIER13080608","url":null,"abstract":"The di-culty of focusing high-resolution highly squinted SAR data comes from the serious azimuth-range coupling, which needs to be compensated in the procedure of imaging. Generally, the linear range walk correction (LRWC) can reduce the coupling efiectively, however, it also induces the problem of azimuth-dependence of residual range cell migration (RCM) and quadratic phase. A novel algorithm is proposed to solve this problem in this paper. In this algorithm, the azimuth nonlinear chirp scaling (ANCS) operation is used, which can not only eliminate the azimuth space variation of residual RCM and frequency modulation (FM) rate but also remove the azimuth misregistration. In addition, the range chirp scaling operation is applied to correct the range-dependent RCM. After implementing the unifled RCM correction, range compression and azimuth compression sequentially, the focused SAR image is acquired flnally. The experimental results with simulated data demonstrate that the proposed algorithm outperforms the existing algorithms.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"49 1","pages":"165-185"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88934747","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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