Table of Content

15 January 2019 Volume 32 Issue 1

  

A Novel Second Order Phase Locked Loop with Adaptive Adjusted Bandwidth

ZHAO Lei,SHI Lei,ZHU Congying,YAO Bo

Electronic Science and Technology. 2019, 32(1):  1-4.  doi:10.16180/j.cnki.issn1007-7820.2019.01.001

Abstract ( 427 )   HTML ( 19 )   PDF (1392KB) ( 67 )  

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The large acquisition bandwidth presents a significant challenge to traditional second-order phase locked loops. On the basis of the contradiction of larger acquisition bandwidth and noise reduction capabilities, a novel second-order PLL which was coupled with a nonlinear element, was introduced in this paper. The loop noise bandwidth was adaptively adjusted by the nonlinear element. The frequency error was reduced more quickly with a larger bandwidth when the frequency error was large. By contrast, the noise was suppressed with a smaller bandwidth to improve the tracking accuracy when the frequency error was reduced due to the control effect of the loop. The simulation results indicated that the tracking speed of the proposed nonlinear second order PLL was significantly increased and the acquisition bandwidth was increased from 4 kHz to 18.8 kHz.

DFT Study on Gas Sensing Property of MoS₂ Monolayer

ZANG Daojun,LI Yunxiang,XU Shuai,WANG Yan

Electronic Science and Technology. 2019, 32(1):  5-10.  doi:10.16180/j.cnki.issn1007-7820.2019.01.002

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For the poor gas sensing property of MoS₂ monolayer, Al doping strategy was employed to improve the dangling bonds inherent defects, thereby enhancing gas sensitivity. Through the calculation of formation energy and electron structure, the doping was confirmed experimentally and the conductivity was enhanced. The gas sensing property of material had gotten vastly improvement through the analysis of adsorption. Especially for ammonia, the adsorption energy and the electron transfer reached to -2.31 eV and 0.38e, respectively. The adsorption length reduced to 1.978 ?. Additionally, the doping basement possessed high selectivity to ammonia gas amid three kinds of gases.

Eliminate the Influence of SMPS Ripple Noise for WiFi Receiver with LMS Algorithms

ZHANG Yan,BU Gang,WANG Mingming

Electronic Science and Technology. 2019, 32(1):  11-15.  doi:10.16180/j.cnki.issn1007-7820.2019.01.003

Abstract ( 436 )   HTML ( 6 )   PDF (1610KB) ( 69 )  

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ing at the problem of ripple when the switching mode power supply was applied to the RF front-end analog circuit, a scheme of eliminating ripple in the digital baseband by using adaptive filtering was proposed. WiFi transceiver system based on IEEE802.11b wireless communication protocol was established by using simulink, and LMS adaptive filter was utilized in digital baseband to suppress the ripple. Simulation results showed that the signal quality could be significantly improved by the adaptive filter. When the ripple amplitude was within 150 mV, the received signal could meet the protocol requirements. Based on these results, an adaptive filter was designed, including both front end and layout. The power consumption analysis showed that the final adaptive filter consumed only 1.35 mW at 33 MHz clock frequency and 1.98 V supply voltage, validating the possibility of using switching mode power supplies for WIFI receivers to achieve significant power savings.

The Design of Low-power Wireless Neural Signal Acquisition Module

YUAN Xudong,ZHU Zhengfei

Electronic Science and Technology. 2019, 32(1):  16-20.  doi:10.16180/j.cnki.issn1007-7820.2019.01.004

Abstract ( 376 )   HTML ( 4 )   PDF (1331KB) ( 53 )  

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In this paper, RF radio frequency principle is used to design a pure analog low power wireless neural signal acquisition module suitable for small animals. Compared with digital-analog hybrid scheme, the pure analog implementation had the advantages of small size, low power consumption and simple structure. The acquisition module were divided into two parts including analog front-end amplification and wireless data transmission. With the use of low-power, low-noise instrumentation amplifier INA333 and OPA333 op amp analog front-end amplifier, a two-stage amplifier structure was formed and the power consumption and size of the circuit was reduced. The feedback enhancement effect achieved by adding a feedback inductor reduced the power consumption of the Colpitts oscillator. The FM modulation of the oscillator used the inter-polar capacitance of the transistor to form a pure analog wireless data transmission circuit, so that the acquisition module had the advantages of small size, low power consumption and wireless data transmission features. Circuit simulation and experimental test results both showed that the module could complete the wireless acquisition of animal neural signals and had a certain practicality.

Research on Virtual Resource Management in Heterogeneous Environment

ZHAO Chuanqi,YUE Chunsheng

Electronic Science and Technology. 2019, 32(1):  21-26.  doi:10.16180/j.cnki.issn1007-7820.2019.01.005

Abstract ( 415 )   HTML ( 9 )   PDF (1148KB) ( 130 )  

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With the continuous development of data processing platform in heterogeneous environment, the importance of virtualization resource management in platform system is increasingly prominent, has attracted more and more attention from the researchers. The traditional high performance homogeneous processing platform can not meet the needs of large amount of complex data processing in the aspects of portable, reconfigurable and expandable. As for the heterogeneous environment of virtual resource management, by introducing the related research progress of heterogeneous hardware and software virtualization and resource management strategy, the existing virtualization resource management strategies are analyzed and summarized. At last, the trend of virtual resource management in the future heterogeneous environment is analyzed.

Design of an Octagonal Ring Antenna Array Applied to Mid-Frequency Aperture Array of Square Kilometer Array

LU Baojun

Electronic Science and Technology. 2019, 32(1):  27-31.  doi:10.16180/j.cnki.issn1007-7820.2019.01.006

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Combined with the application scenarios of square kilometer array, an ultra-wideband octagonal ring antenna element based on the resistive frequency selective surface was presented. The standing wave protrusion caused by the reverse phase superposition of the reflection plate at the corresponding frequency point could be effectively suppressed by inserting a square ring resistive frequency selective surface between antenna array and ground plane, which greatly improved impedance bandwidth and reduced the profile of antenna array. Simulation results indicated that based on the resistive frequency selective surface, a 5:1 impedance matching bandwidth was obtained within the ±45° scanning range. At the same time, the profile of the antenna had been also reduced by about 27%. In addition, the antenna element had a stable active pattern, wide half-power lobe width and good polarization performance over the entire operating band.

Finger Vein Authentication Technology Based on Image Registration

JIN Xiaofeng,WANG Dandan,LIANG Tiancai,XU Jun,WANG Biao

Electronic Science and Technology. 2019, 32(1):  32-37.  doi:10.16180/j.cnki.issn1007-7820.2019.01.007

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Venous distortion and image shadow that result from finger rotation and posture change during finger vein capture affect the accuracy of finger vein authentication. Therefore, this paper proposed a finger vein authentication method based on image registration, which authenticated the images by registering a few stable feature points, and extracting the texture features of the two registered images. In this method, it firstly selected the clues with high resolution in the neighborhood as the feature points, then matched the feature points and registered the two images. Finally, the similarity of the two registration images were calculated according to the texture features. The proposed method mainly overcame the problem of small number of points in the method based on feature point matching and solved the problem of venous deformation. Experimental results showed that this method had better performance than template matching and feature point matching.

Scene Recognition Algorithm Based on Sparse Autoencoder

XIE Lin,LI Feifei,CHEN Qiu

Electronic Science and Technology. 2019, 32(1):  38-41.  doi:10.16180/j.cnki.issn1007-7820.2019.01.008

Abstract ( 427 )   HTML ( 8 )   PDF (1156KB) ( 36 )  

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To narrow the gap between low-level features and high-level concepts in scene recognition, a new algorithm based on the sparse autoencoder was proposed. This algorithm adopted the feature encoding technique that combined the sparse autoencoder and spatial pyramid pooling. First of all, the local HOG descriptors were extracted from scene images, then they were encoded into sparse features by the modified sparse autoencoder. After spatial pyramid pooling and local normalization on these sparse features, the image representation can be obtained. Finally, linear SVM was utilized to implement scene recognition. The experimental results on Scene-15 dataset indicated that the recognition accuracy of this algorithm can be increased up to 81.97%.

Design and Implementation of an Electrically Tunable Filter with High Suppression

LIU Lele,LIU Lan,SHI Yu,WU Zhilin,HU Yue,WEN Jie

Electronic Science and Technology. 2019, 32(1):  42-46.  doi:10.16180/j.cnki.issn1007-7820.2019.01.009

Abstract ( 554 )   HTML ( 15 )   PDF (1356KB) ( 73 )  

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For the demand of wide frequency band, low loss and high external restriction in the front preselection of superheterodyne receiver, a filter was increased to suppress the spurious band behind the LC electrically tunable filter with inductance coupling method in the article, designing an electrically tunable filter on account of 20~800 MHz . Actual test showed that in the tuning range, insertion loss of the filter was less than 1.5 dB, 1 dB bandwidth was about 20%~30%, VSWR of input and output ports were less than 1.5, suppression on the second harmonic frequency was more than 40 dBc. The suppression on the spurious band was increased more than 40 dBc in the second frequency and more than 30 dBc in the third harmonic frequency after applying this filter. All these benefited to the filter with the intermediate frequency suppression, mirror frequency suppression, the reverse leakage of vibration suppression, and so on.

Texture-less Object Detection Algorithm with Speed-up Based on Template Matching

QIN Haibao

Electronic Science and Technology. 2019, 32(1):  47-51.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0010

Abstract ( 356 )   HTML ( 4 )   PDF (1250KB) ( 42 )  

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The traditional template-based matching algorithms generally consider the integrity of the template, which brings often the problem of computational complexity. This paper proposed a fast approach to texture-less object detection based on the binarized orientation compressed map and local feature weighting. According to the quantized gradient orientation of the edge points, the proposed method described the representation of the template features by using the orientation compressed map, which could estimate object candidate locations and corresponding scale and rotation information with fast-speed. After the detection of the object candidate locations, a new template feature was built based on the local feature weighting, and the novel similarity of the object candidate locations was calculated to determine the final pose of the object. Experiments showed that the proposed method had better recognition rate than other representative algorithms, and the recognition speed was greatly improved.

Vector Control System of PMSM Based on Repetitive Synovial Control

JI Chuankun,QIAN Junbing

Electronic Science and Technology. 2019, 32(1):  52-57.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0011

Abstract ( 607 )   HTML ( 8 )   PDF (1605KB) ( 62 )  

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ing at the chattering phenomenon of permanent magnet synchronous motor (PMSM) when the load was abrupt, a repetitive synovial control method was proposed. Firstly, the article introduced the mathematical model of permanent magnet synchronous motor and the basic principle of synovial variable structure in detail, and a synovial control strategy was applied to replace the traditional PI control in speed loop of PMSM. Secondly, the basic principle of repetitive control was comprehensively analyzed. On the basis of synovial control, repetitive control was added to the control system. And proposed a new type of repetitive synovial control approach, a motor simulation model based on MATLAB/Simulink was established. The simulation result shows that the scheme has better system responsiveness in the rising stage of motor speed; when the motor load is abrupt, the maximum mutation value of motor speed is reduced by 74.55% compared with the use of the synovial control, and the time of motor returns to the stable state also becomes 37.5% of the original; it is verified that the presented repetitive synovial control algorithm has strong load resistance and system stability.

Reactive Power Optimization of Power System Based on Electronic Search Algorithm

HUANG Taixiang,CHEN Bo,GUAN Xin,CHENG Luyao

Electronic Science and Technology. 2019, 32(1):  58-61.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0012

Abstract ( 339 )   HTML ( 8 )   PDF (992KB) ( 32 )  

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Aiming at the slow convergence of PSO and the problem that the result of PSO was easy to fall into local solution in the reactive power optimization process of power system, the electro-search algorithm was used instead of PSO to improve the convergence speed and make the optimization calculation easier to get the optimal solution. In order to minimize the expected loss, a reactive power optimization model for distribution network was established, which considered the capacitor reactive power compensation and the voltage transformer ratio. The simulation results of IEEE 14 bus system verified the effectiveness of the electro-search algorithm in reactive power optimization. Finally, the results of particle swarm optimization and electro-search algorithm were compared. The results showed that the electro-search algorithm was superior to particle swarm optimization in convergence speed and optimization effect.

Resolution Capability Analysis of BISAR System Based on Different Navigation Signals

ZHANG Lei,WAN Chaofan,YIN Zhiping

Electronic Science and Technology. 2019, 32(1):  62-66.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0013

Abstract ( 367 )   HTML ( 8 )   PDF (1263KB) ( 36 )  

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The BISAR system based on navigation satellite signals attracted more and more attention for its advantages. The concept of average ambiguity function was introduced in this paper in order to analyze the resolution capability of BISAR system independently of the particular pseudo-random code, and the generalized ambiguity function (GAF) of the system was studied. Then average GAFs of BISAR system based on different GNSS signals were calculated to compare their resolution performance. The results indicated that the trajectory of navigation satellite had a great influence on the performance of the BISAR system and BDS signal had the best resolution capability.

Ultrasound Imaging Based on Predistortion Coded Excitation and Minimum Variance Beamforming

KANG Weixin,GONG Xue,LIU Yumei,WANG Hongru

Electronic Science and Technology. 2019, 32(1):  67-71.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0014

Abstract ( 351 )   HTML ( 6 )   PDF (1245KB) ( 80 )  

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In order to improve the axial resolution of medical ultrasound imaging, an imaging method based on predistortion coded excitation and improved minimum variance was proposed. On the one hand, this method compensated the influence of the probe on the signal and improved the resolution of the emitter through the predistortion and sidelobe reduction technology of the coded excitation signal. On the other hand, the improved minimum variance beamforming was applied, which effectively improved the resolution of medical ultrasound imaging and improved the robustness of adaptive algorithm. The simulation results showed that the proposed method obtained better performance than the constant envelope excitation and the conventional delay-and-sum beamformer algorithms in the imaging resolution and robustness. Meanwhile, the algorithm provided theory evidence for the realization of high-quality ultrasonic image system.

Classification Performance of Compressing Dimensionality of Hidden Layer of Deep Neural Network

CHENG Lingfei,HE Yang,ZHANG Peiling,LI Yan

Electronic Science and Technology. 2019, 32(1):  72-75.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0015

Abstract ( 386 )   HTML ( 4 )   PDF (1054KB) ( 95 )  

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In order to make deep neural network get better generalization property and reduce training time. Inspired by compressed neural network, compressing dimension of the hidden layers according to different compression ratio, and based on the traditional compressed deep neural network, adding classification layer to the top layer, then deep neural network gets the ability of classification. Experiments performed on MNIST handwritten dataset show that using properly compress deep neural network instead of uncompressed network would get better classification results, and saving lots of training time.

Design of a Programmable High Anti-interference AGC

WEN Jie,WU Zhilin,SHI Yu,LIU Lan,HU Yue,LIU Lele

Electronic Science and Technology. 2019, 32(1):  76-79.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0016

Abstract ( 469 )   HTML ( 4 )   PDF (995KB) ( 46 )  

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In the RF receiving system, Automatic Gain Control (AGC) circuit can effectively improve the dynamic range of the receiver. A programmable high anti-interference AGC circuit was designed to realize AGC by means of “narrow-band filter+logarithmic amplifier+analog-to-digital conversion+microcontrollers”. Through the practical test, in four conditions (including initial Signal Noise Ratio, SNR deteriorates 30 dB, 60 dB and 85 dB), the gain dynamic range reached 32 dB, and the power error of the output signal was less than 0.5 dB. It was shown that the structure of the circuit can still work normally in the bad SNR environment and had good anti-interference ability.

The Fire Protocol Intelligent Analysis Model Based on Deep Learning

SHI Ce,QIU Jiong

Electronic Science and Technology. 2019, 32(1):  80-85.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0017

Abstract ( 414 )   HTML ( 7 )   PDF (1419KB) ( 51 )  

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The automatic fire alarm had many brands and models, The data protocols of different brands or models were not the same, which made it difficult for information integration of smart fire.To solve the problem,this paper presented a SSAESMFA model that combined deep learning technology with Fire protocol intelligent analysis model.The model based on stack sparse auto encoder and softmax regression,provided the identification of unknown protocol data through deep learning of known protocol data of fire equipment.After training, The accuracy of SSAESMFA in identifying fire alarm protocol was 99.83%, Experiments showed that the model had a high feature extraction and classification ability of fire equipment protocol data,effectively improved the efficiency of information integration of smart fire.

Kinect Obstacle Detection Algorithm Based on DBSCAN and Aradient Partition

PAN Di

Electronic Science and Technology. 2019, 32(1):  86-90.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0018

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For the environment detection and obstacle avoidance problems of mobile robots, the information acquired by the sensors was not comprehensive and accurate, and it was impossible to accurately provide information about the surrounding environment. In this paper, the use of Kinect sensors to obtain the color information and depth data of the surrounding environment was proposed. A depth data map obtained by the Kinect sensor using gradient partitioning and DBSCAN clustering method. Firstly, the gradient obstacle edge detection method was used to quickly and efficiently process the edge contour of the obstacle obtained by Kinect, and the difference parameters in the algorithm are improved, so that the calculated gradient result was more accurate. Then compare the different clustering methods, use BDSCAN clustering method to cluster the detected obstacles, and finally verify the algorithm by arranging specific experiments. The experimental results showed that the algorithm can accurately divide the surrounding obstacles, and the feasible area was effective. The successful detection rate for different objects was more accurate. The validity of the algorithm was verified.

Simulation Model of High Voltage Circuit Breaker Based on PSCAD

KE Haoyun,CHEN Tie,XIAO Yu

Electronic Science and Technology. 2019, 32(1):  91-94.  doi:10.16180/j.cnki.issn1007-7820.2019.01.0019

Abstract ( 815 )   HTML ( 19 )   PDF (1478KB) ( 118 )  

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The circuit breaker was the most important control and protection device in the power system. However, the switching state was only simply represented by most of the existing circuit breaker models, so a circuit breaker based on dynamic arc was established. Firstly, the selected arc model was analyzed to obtain the required parameters. Then, the circuit breaker simulation model was built in PSCAD/EMTDC. The algorithm was programmed for the arc model in MATLAB, and MATLAB was called by special interface in PSCAD. Through the simulation research and comparison, the voltage and current of the breaker when the fault was cut off was basically consistent with the theoretical analysis. The correctness of the circuit breaker model was verified, which showed that the design model had a certain reference.