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Wideband CMOS variable gain amplifier with decibel-linear gain control characteristic

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the Journal of china Universities of Posts and Telecommunications 2019年第1期26卷 59-64页

作者： Dun Shubo Li Bin Shi Guochao Yang Geliang the 54th research institute of china electronics technology group corporation

this paper presents a wideband variable gain amplifier(VGA) featuring a decibel-linear gain control characteristic. the decibel-linear gain control function is realized using two VGA cells and a control signal converter. the bandwidth is extended by using cascode architecture together with active inductive load. To achieve small parasitic and low area,direct current(DC) coupling is adopted in the circuit while a DC offset cancellation(DCOC) circuit is introduced to cancel the DC offset. Fabricated in a 0.18 μm complementary metal oxide semiconductor(CMOS) process, the chip occupies an area of 0.53 mm×0.48 mm(including pads) and draws a total current of 9 mA from a 1.8 V supply. the measurement results show that the gain of the VGA varies from-40 dB to 18 dB while the control voltage varies from 0 to 1.8 V, resulting in a total gain control range of 58 dB. the 3 dB bandwidth of the VGA is larger than 260 MHz at maximum gain.

关键词： variable gain amplifier exponential gain control DC offset cancellation wideband

Adaptive Generalized Eigenvector Estimating Algorithm for Hermitian Matrix Pencil

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IEEE/CAA Journal of Automatica Sinica 2022年第11期9卷 1967-1979页

作者： Yingbin Gao the 54th research institute of china electronics technology group corporation(CETC54) Shijiazhuang 050050China

Generalized eigenvector plays an essential role in the signal processing *** this paper,we present a novel neural network learning algorithm for estimating the generalized eigenvector of a Hermitian matrix *** from some traditional algorithms,which need to select the proper values of learning rates before using,the proposed algorithm does not need a learning rate and is very suitable for real *** analyzing all of the equilibrium points,it is proven that if and only if the weight vector of the neural network is equal to the generalized eigenvector corresponding to the largest generalized eigenvalue of a Hermitian matrix pencil,the proposed algorithm reaches to convergence *** using the deterministic discretetime(DDT)method,some convergence conditions,which can be satisfied with probability 1,are also obtained to guarantee its *** results show that the proposed algorithm has a fast convergence speed and good numerical *** real application demonstrates its effectiveness in tracking the optimal vector of beamforming.

关键词： Deterministic discrete-time(DDT) generalized eigenvector learning rate online estimation

Fast PARAFAC decomposition with application to polarization sensitive array parameter estimations

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Journal of Systems Engineering and electronics 2018年第4期29卷 714-722页

作者： LI Yang the 10th research institute China Electronics Technology Group Corporation

In tensor theory, the parallel factorization （PARAFAC）decomposition expresses a tensor as the sum of a set of rank-1tensors. By carrying out this numerical decomposition, mixedsources can be separated or unknown system parameters can beidentified, which is the so-called blind source separation or blindidentification. In this paper we propose a numerical PARAFACdecomposition algorithm. Compared to traditional algorithms, wespeed up the decomposition in several aspects, i.e., search di-rection by extrapolation, suboptimal step size by Gauss-Newtonapproximation, and linear search by n steps. the algorithm is ap-plied to polarization sensitive array parameter estimation to showits usefulness. Simulations verify the correctness and performanceof the proposed numerical techniques.

关键词： tensor decomposition parallel factorization(PARAFAC) alternating least squares (ALS) polarization sensi-tive array (PSA)

Genetic-optimization framework for SVC transmission based on partial cooperative communication

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Journal of Systems Engineering and electronics 2017年第5期28卷 861-870页

作者： Kai Zhao Yongcheng Sun the 28th research institute of china electronics technology group corporation

A genetic-optimization framework based on the partial cooperation communication protocol is proposed for scalable video coding (SVC) stream transmission under multi-relay amplify and forward cooperative networks. Unlike traditional cooperative transmission schemes, the transmission mode for each coded unit in this new protocol can be switched flexibly between direct transmission and cooperative transmission. Obviously, under this protocol, the bandwidth efficiency and transmission robustness can be balanced adaptively according to the priority level of coded units and wireless channel fading characteristics. Based on this, a well-known genetic optimization algorithm-differential evolution is exploited here to find the jointly optimal transmission modes, power allocation and unequal error protection (UEP) channel coding strategies to minimize the end to end reconstructed video distortion. Extensive simulation results show that, compared with classical optimal cooperative UEP transmission schemes, the proposed optimized transmission framework based on the partial cooperative protocol can bring significant peak-signal-to-noise-ratio (PSNR) gains for the reconstructed video in a variety of channel bandwidth, power budget and test sequences.

关键词： scalable video coding partial cooperative communication unequal error protection source-relay power allocation differential evolution

Joint Bayesian and Greedy Recovery for Compressive Sensing

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Chinese Journal of electronics 2020年第5期29卷 945-951页

作者： LI Jia china electronics technology group corporation 54th research institute Hebei Key Laboratory of Electromagnetic Spectrum Cognition and Control

Greedy algorithms are widely used for sparse recovery in compressive sensing. Conventional greedy algorithms employ the inner product vector of signal residual and sensing matrix to determine the support, which is based on the assumption that the indexes of the larger-magnitude entries of the inner product vector are more likely to be contained in the correct ***, this assumption may be not valid when the number of measurements is not sufficient, leading to the selection of an incorrect support. To improve the accuracy of greedy recovery, we propose a novel greedy algorithm to recover sparse signals from incomplete *** entries of a sparse signal are modelled by the type-II Laplacian prior, such that the k indexes of the correct support are indicated by the largest k variance hyperparameters of the entries. Based on the proposed model, the supports can be recovered by approximately estimating the hyperparameters via the maximum a posteriori process. Simulation results demonstrate that the proposed algorithm outperforms the conventional greedy algorithms in terms of recovery accuracy, and it exhibits satisfactory recovery speed.

关键词： Sparse recovery Compressive sensing Greedy algorithm Laplacian prior

Direction estimation for two steady targets in monopulse radar

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Journal of Systems Engineering and electronics 2015年第1期26卷 61-68页

作者： Zhenxing Lu Yunjie Li Meiguo Gao School of Information and electronics Beijing Institute of Technology the 54th research institute China Electronics Technology Group Corporation

Traditional monopulse radar cannot resolve two targets present in one range and Doppler cell by means of the monopulse ratio. A novel algorithm is proposed to estimate the directions of two steady targets with two pulses. the algorithm has a closedform expression and its variance is derived at high signal-to-noise ratios（SNRs）. Furthermore, the pulse pair selection criterion and the estimation method with multiple pulses are given. Finally, some numerical results are shown to validate the proposed algorithm and the effect of slight target fluctuations is tested.

关键词： direction estimation two unresolved targets monopulse radar

In-flight performance analysis of the navigation augmentation payload on LEO communication satellite:a preliminary study on WT01 mission

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Geo-Spatial Information Science 2022年第1期25卷 88-103页

作者： Ziqian Wu Baoguo Yu Chuanzhen Sheng Jingkui Zhang Song Xie Cailun Wu State Key Laboratory of Satellite Navigation System and Equipment technology ShijiazhuangChina the 54th research institute of china electronics technology group corporation ShijiazhuangChina

With the development of the Low Earth Orbit(LEO)communication constellations,it has become a hot area of research to provide additional navigation augmentation *** by volume,weight,power consumption,and running time,the in-flight performance of navigation augmentation payload remains to be *** this paper,we analyze the data quality of on-board GNSS observation and evaluate the precision of short-arc dynamic Precise Orbit Determination(POD)performance based on the WangTong-01(WT01)***,the downlink navigation measurement data of WT01 satellites are analyzed and compared with the GNSS *** results show that the average multipath errors of the WT01 on-board GPS L1,L2 and BeiDou Satellite Navigation System(BDS)B1,B2 code observation are 0.54,0.74,0.65,and 0.58 m,*** short-arc dynamic POD three-dimensional(3D)overlapping accuracy is 7.1 *** average multipath errors of downlink navigation signal Z1 and Z2 are 0.81 and 0.80 m,respectively,which at the same order of magnitude as GNSS *** maximum Carrier-to-Noise Ratio(C/N0)value of WT01 downlink measurement data can reach 60 dB Hz,which is much stronger than GNSS and indicates the navigation signals of LEO satellites can meet the basic requirement of navigation augmentation.

关键词： Navigation payload in-flight performance augmentation communication satellites LEO

A Probabilistic Approach for Predicting Vessel Motion

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1877-1879页

作者： Qi Hu Jingyi Liu Zongyu Zuo 7th research Division Beihang University(BUAA)Beijing 100191China 54th research institute of china electronics technology group corporation Shijiazhuang 050081China

Dear Editor,this letter addresses the challenge of forecasting the motion of real-world vessels over an extended period with a limited amount of available *** employing stochastic differential equation(SDE)modeling,we integrate both deterministic and stochastic components of the available ***,we establish a recursive prediction methodology based on Bayes’rule to update the model state when new measurements are ***,we develop a stochastic model tailored specifically to vessel dynamics and introduce an approximation method to tackle computational ***,we present an application example and conduct a comparative experiment to validate the effectiveness and superiority of the proposed method.

关键词： method stochastic letter

SOI-based radial-contour-mode micromechanical disk resonator

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Journal of Semiconductors 2011年第11期32卷 72-76页

作者：贾英茜赵正平杨拥军胡晓东李倩 School of Information Engineering Hebei University of Technology the 13th research institute China Electronics Technology Group Corporation china electronics technology group corporation

this paper reports a radial-contour-mode micromechanical disk resonator for radio frequency applications. this disk resonator with a gold plated layer as the electrodes, was prepared on a silicon-on-insulator wafer, which is supported by an anchor on another silicon wafer through Au-Au thermo-compression bonding. the gap between the disk and the surrounding gold electrodes is 100 nm. the radius of the disk is 20μm and the thickness is 4.5 μm. In results, the resonator shows a resonant frequency of 143 MHz and a quality factor of 5600 in vacuum

关键词： RF-MEMS micromechanical disk resonator SOI, thermo-compression bonding