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A millimeter and sub-millimeter wave frequency selective surface beamsplitter for geostationary orbit microwave radiometers

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Chinese Physics B 2012年第11期21卷 214-221页

作者：崔广斌赵海博张勇芳苗俊刚 microwave engineering laboratory Beihang University

We report the design of three frequency selective surface （FSS） filters used on the FengYun-4 （FY-4） microwave satellite, which separate five-frequency bands in the frequency range of 50-429 GHz with the insertion loss less than 0.4 dB, and separation between adjacent channels more than 20 dB for either TE or TM incidence. Firstly, we briefly introduce the disadvantages of two types of FSS filter： waveguide-array FSS and printed FSS, which are commonly employed in the millimeter and sub-millimeter wave band. In order to meet the insertion loss requirement and specified spectral transmission response, we adopt a filter composed of two closely spaced freestanding metal plates, which con- tains an array of resonant ring slot elements. Computer simulation technology （CST） is used to optimize the structural dimensions of the resonant unit and interlayer separation. Numerical results show that these FSS filters exhibit trans- mission loss of less than 0.4 dB and separation between adjacent channels of more than 20 dB. Simulated transmission coefficients are in close agreement with the required specification, and even exceed the performance specifications.

关键词： millimeter and sub-millimeter wave frequency selective surface quasi-optical system

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microwave photonics

Science China(Information Sciences) 2022年第12期65卷 49-112页

作者： Jianping YAO Jose CAPMANY microwave photonics Research laboratory School of Electrical Engineering and Computer Science University of Ottawa ITEAM Research Institute Universitat Politècnica de València iPronics Programmable Photonics

microwave photonics, an interdisciplinary field that combines microwave engineering and photonic technology for the generation, transmission, processing, and control of microwave signals, to take advantage of the broad bandwidth, high frequency, and low loss offered by modern photonics, has been intensively researched for the last few decades, and numerous solutions have been proposed and demonstrated. In this article, an overview about microwave photonics is provided which covers the basic concepts of microwave photonics, photonic-assisted microwave signal generation, photonic-assisted microwave signal processing, and true time delay beamforming. The implementation of microwave photonic systems based on photonic integrated circuits is also reviewed, including the design, fabrication, and material platforms, application-specific photonic integrated circuits for microwave photonics, and programmable integrated microwave *** challenges and future applications of microwave photonics are also discussed.

关键词： microwave photonics photonic integrated circuits microwave photonic link microwave photonic signal processor optoelectronic oscillator radio over fiber

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Evaluation of Trajectory Error Effects in BP Based Space Target ISAR Imaging

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第6期35卷 913-923页

作者： Wang Ling Wang Jie Sun Lingling Key laboratory of Radar Imaging and microwave photonics Ministry of EducationCollege of Electronic and Information EngineeringNanjing University of Aeronautics and Astronautics

The space target imaging is important in the development of space *** to the availability of trajectory information of the space targets and the arising of rapid parallel processing hardware,the back projection (BP) method has been applied to synthetic aperture radar (SAR) imaging and shows a number of advantages as compared with conventional Fourier-domain imaging ***,the practical processing shows that the insufficient accuracy of the trajectory information results in the degrading of the imaging *** the other hand,the autofocusing algorithms for BP imaging are not well developed,which is a bottleneck for the application of BP ***,an analysis of the effect of trajectory errors on the space target imaging using microlocal technology is *** analysis provides an explicit quantitative relationship between the trajectory errors of the space target and the positioning errors in the reconstructed *** explicit form of the position errors for some typical trajectory errors is also *** simulations demonstrate our theoretical *** measured position errors obtained from the reconstructed images are consistent with the analytic errors calculated by using the derived *** results will be used in the development of effective autofocusing methods for BP imaging.

关键词： inverse synthetic aperture radar(ISAR) imaging space targets trajectory error back projection(BP)

Wigner-Matrix-Based Normality Test and Application to Weak Signal Detection in SISO/SIMO Systems

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Chinese Physics Letters 2016年第12期33卷 1-4页

作者：陈军汪飞周建江 Key laboratory of Radar Imaging and microwave photonics(Ministry of Education) Nanjing University of Aeronautics and Astronautics

Based on the asymptotic spectral distribution of Wigner matrices, a new normality test method is proposed via reforming the white noise sequence. In this work, the asymptotic cumulative distribution function （CDF） of eigenvalues of the Wigner matrix is deduced. A numerical Kullback-Leibler divergence of the empiric-d spectral CDF based on test samples from the deduced asymptotic CDF is established, which is treated as the test statistic. For validating the superiority of our proposed normality test, we apply the method to weak SIPSK signal detection in the single-input single-output （SISO） system and the single-input multiple-output （SIMO） system. By comparing with other common normality tests and the existing signal detection methods, simulation results show that the proposed method is superior and robust.

关键词： SIMO of is with CDF Wigner-Matrix-Based Normality Test and Application to Weak Signal Detection in SISO/SIMO Systems SISO in

Ultra-wideband surface plasmonic bandpass filter with extremely wide upper-band rejection

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Chinese Physics B 2022年第11期31卷 303-308页

作者： Xue-Wei Zhang Shao-Bin Liu Qi-Ming Yu Ling-Ling Wang Kun Liao Jian Lou College of Electronic and Information engineering Key Laboratory of Radar Imaging and Microwave PhotonicsMinistry of EducationNanjing University of Aeronautics and AstronauticsNanjing 211106China

An ultra-wideband bandpass filter(BPF)with a wide out-of-band rejection based on a surface plasmonic waveguide(SPW)slotline with ring grooves is designed and analyzed.A paired microstrip-to-slotline transition is designed for quasiTEM to TM mode conversion by using a microstrip line with a circular pad and the slotline with the same circular *** mode conversion between the TM and the surface plasmon polariton(SPP)mode is realized by using a gradient slotline with ring grooves and an impedance matching *** upper cut-off frequencies of the passband can be adjusted by using these proposed SPP units,while the lower frequencies of the passband are created by using the microstrip-toslotline transitions to give an ultra-wideband *** dispersion curves of SPP units,electric field distribution,and the transmission spectra of the proposed ultra-wideband bandpass filter are all calculated and analyzed by the finite-difference time-domain(FDTD)*** simulated results show that the presented filter has good performance including a wide3-dB bandwidth of 149%from 0.57 GHz to 3.93 GHz,an extremely wide 40-dB upper-band rejection from 4.2 GHz to18.5 GHz,and low loss and high selectivity in the *** prove the design validity,a prototype of the BPF has been manufactured and measured,showing a reasonable agreement with simulation *** unique features of the proposed BPF may make it applicable for integrated circuit and plasmonic devices in microwave or THz frequency ranges.

关键词： surface plasmonic waveguide(SPW) bandpass filter out-of-band rejection ultra-wideband

A Special Sampling Structure with an Arbitrary Equivalent-Phase-Shift for Semiconductor Lasers and Multiwavelength Laser Arrays

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Chinese Physics Letters 2011年第7期28卷 140-143页

作者： ZHOU Ya-Ting SHI Yue-Chun LI Si-Min LIU Sheng-Chun CHEN Xiang-Fei microwave-photonics Technology laboratory Nanjing National Laboratory of MicrostructuresSchool of Engineering and Applied SciencesNanjing UniversityNanjing 210093 Changzhou Institute of Technology Changzhou 213002

A method used to introduce an arbitrary equivalent-phase-shift(EPS)into an asymmetric sampled Bragg grating(SBG)is *** the same structural parameters except for the sampling pattern,the asymmetric SBG offers better performance than that of a normal SBG structure for keeping single-longitudinal-mode(SLM)*** is because the proposed sampling pattern can suppress the 0th-order light resonance due to the mismatch between the two different grating sections along the whole *** method can be used to design and fabricate semiconductor lasers and multiwavelength laser arrays(MLAs)with the required EPS at high yield and low cost.

关键词： asymmetric pattern Shift

A Real-Valued 2D DOA Estimation Algorithm of Noncircular Signal via Euler Transformation and Rotational Invariance Property

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第3期35卷 437-448页

作者： Chen Xueqiang Wang Chenghua Zhang Xiaofei Key laboratory of Radar Imaging and microwave photonics Nanjing University of Aeronautics and Astronautics College of Electronic and Information engineering Nanjing University of Aeronautics and Astronautics

The problem of two-dimensional(2 D)direction of arrival(DOA)estimation for double parallel uniform linear arrays is investigated in this paper.A real-valued DOA estimation algorithm of noncircular(NC)signal is proposed,which combines the Euler transformation and rotational invariance(RI)property between *** this work,the effective array aperture is doubled by exploiting the noncircularity of *** complex arithmetic is converted to real arithmetic via Euler *** main contribution of this work is not only extending the NC-Euler-ESPRIT algorithm from uniform linear array to double parallel uniform linear arrays,but also constructing a new 2 Drotational invariance property between subarrays,which is more complex than that in NCEuler-ESPRIT *** proposed 2 DNC-Euler-RI algorithm has much lower computational complexity than2 DNC-ESPRIT *** proposed algorithm has better angle estimation performance than 2 DESPRIT algorithm and 2 D NC-PM algorithm for double parallel uniform linear arrays,and is very close to that of 2 D NC-ESPRIT *** elevation angles and azimuth angles can be obtained with automatically *** proposed algorithm can estimate up to 2(M-1)sources,which is two times that of 2 D ESPRIT ***-Rao bound(CRB)of noncircular signal is derived for the proposed *** complexity comparison is also ***,simulation results are presented to illustrate the effectiveness and usefulness of the proposed algorithm.

关键词： array signal processing direction of arrival(DOA)estimation noncircular signal Euler transformation

Direction-of-arrival estimation for co-located multiple-input multiple-output radar using structural sparsity Bayesian learning

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Chinese Physics B 2015年第11期24卷 70-76页

作者：文方青张弓贲德 College of Electronic and Information engineering Nanjing University of Aeronautics and Astronautics Key laboratory of Radar Imaging and microwave photonics Ministry of Education Nanjing Research Institute of Electronics Technology

This paper addresses the direction of arrival （DOA） estimation problem for the co-located multiple-input multiple- output （MIMO） radar with random arrays. The spatially distributed sparsity of the targets in the background makes com- pressive sensing （CS） desirable for DOA estimation. A spatial CS framework is presented, which links the DOA estimation problem to support recovery from a known over-complete dictionary. A modified statistical model is developed to ac- curately represent the intra-block correlation of the received signal. A structural sparsity Bayesian learning algorithm is proposed for the sparse recovery problem. The proposed algorithm, which exploits intra-signal correlation, is capable being applied to limited data support and low signal-to-noise ratio （SNR） scene. Furthermore, the proposed algorithm has less computation load compared to the classical Bayesian algorithm. Simulation results show that the proposed algorithm has a more accurate DOA estimation than the traditional multiple signal classification （MUSIC） algorithm and other CS recovery algorithms.

关键词： multiple-input multiple-output radar random arrays direction of arrival estimation sparseBayesian learning

Estimation of multipath parameters in wireless communications using multi-way compressive sensing

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Journal of Systems engineering and Electronics 2015年第5期26卷 908-915页

作者： Fangqing Wen Gong Zhang De Ben College of Electronics and Information engineering Nanjing University of Aeronautics and Astronautics Key laboratory of Radar Imaging and microwave photonics Ministry of Education Nanjing Research Institute of Electronics Technology

This paper addresses the problem of joint angle and delay estimation(JADE) in a multipath communication scenario. A low-complexity multi-way compressive sensing(MCS) estimation algorithm is proposed. The received data are firstly stacked up to a trilinear tensor model. To reduce the computational complexity,three random compression matrices are individually used to reduce each tensor to a much smaller one. JADE then is linked to a low-dimensional trilinear model. Our algorithm has an estimation performance very close to that of the parallel factor analysis(PARAFAC) algorithm and automatic pairing of the two parameter sets. Compared with other methods, such as multiple signal classification(MUSIC), the estimation of signal parameters via rotational invariance techniques(ESPRIT), the MCS algorithm requires neither eigenvalue decomposition of the received signal covariance matrix nor spectral peak searching. It also does not require the channel fading information, which means the proposed algorithm is blind and robust, therefore it has a higher working *** results indicate the proposed algorithm have a bright future in wireless communications.

关键词： multipath channel delay estimation direction-ofarrival(DOA) estimation multi-way compressive sensing(MCS)