Electronic Science and Technology

Analysis and Processing of Weak Signal Noise in Synthetic Aperture Ladar

WANG Li-Li, ZENG Xiao-Dong

. 2010, 23(9): 1.

Abstract ( 1437 )

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An analysis of the major noise sources of PIN optoelectronic diode is made.Bias circuit and filter circuit are designed.Electromagnetic shielding is reasonably used with the effect exerted by high frequency in mind.Experiment shows that the noise of the system is significantly decreased and the SNR is improved by the use of the bias circuit and filter circuit.It enjoys great possibility for SAL to be applied in practical application.

Research on Weighted Noise Frequency Modulated Jamming Countering Inverse Synthetic Aperture Radar

YANG Xiao-Guang, WAN Ling-Da

. 2010, 23(9): 4.

Abstract ( 1432 )

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Inverse synthetic aperture radar (ISAR) is playing an important role in the military,and the research on the jamming countering ISAR has been continuously made.This paper makes a study of a coherent jamming method for countering ISAR,namely,weighted noise frequency modulated jamming.Weighted noise frequency modulated jamming can obtain some processing gain related to the conventional noise frequency modulated jamming,thus saving the jamming power.

Development of the Anti-glimpse Door Mirror

CHEN Yu

. 2010, 23(9): 8.

Abstract ( 1164 )

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By using infrared detection technology and optical switching characteristics of liquid crystal cell,a new path has been opened for the technology for the anti-glimpse door mirror.This paper outlines the structure and working principle of anti-glimpse door mirror,introduces the key technologies for the process design and circuit design.After final assembly and circuit debugging,results show that such anti-glimpse door mirror meets the requirement for practical application.

Design of Data Communication System for Sonar Based on Two-double Can Bus

WANG Dan, HUA Hong-Yan, ZHAO Song

. 2010, 23(9): 10.

Abstract ( 2009 )

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In view of the problems existing in boat sonar signal acquisition of regional broad and large volumes of data,we present a data communication system for sonar based on two-double can bus.At the heart of system is a PIC18F4580 MCU controller,it uses its own integrated CAN controller to communication with the acquisition unit node,and uses an external CAN controller MCP2510 to communicate with the computer.CAN bus interface to realized two-double and multi-regional data collection.Experimental results show that no data transmission error or loss,the system performance is stable and reliable.

Back-end Design of Electronic Products Panel Controller Chips

WANG Ren-Peng, SHI Long-Zhao

. 2010, 23(9): 14.

Abstract ( 1153 )

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This paper introduces the layout design of electronic products panel controller chip during Huahong NEC 0.35 μm CZ6H 1P3AL process by SOC Encounter.In the layout design,a good placing effect is achieved by using time-driven placement and limiting placement density.A combination of clock tree automatic synthesis and manual modification reduces the clock skew to the minimum degree.Problems resulting from power network connection and routing violations are solved.At last,the chip meets the demand of both timing and technology,reaching the following target: the working frequency of 12 MHz,the chip area of 1.089 mm² and the power dissipation of 2.715 2 mW.

Research on the Novel CRLH-TL Based on the Micro-strip Structure

CAO Zhi, TIAN Hui

. 2010, 23(9): 18.

Abstract ( 1199 )

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The paper gives an introduction to a novel composite right/left-handed transmission line (CRLH-TL) meta-material with two pass bands as well as its operation and analysis method.In this meta-material,the permittivity and permeability are both negative.The two pass bands of the CRLH-TL exist at 2.8 GHz and 5.8 GHz,respectively.Simulation yields dispersion curves,index of refraction,permittivity and permeability,theoretically verifying the existence of left-handed metamaterials.

Design of a Voltage Source with a Bandgap Reference

HE Wei

. 2010, 23(9): 21.

Abstract ( 1566 )

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Based on TSMC0.5 μm CMOS,a circuit with a bandgap reference is designed in this paper.The circuit employs an arithmetic amplifier to implement the internal negative feedback in comparison with the traditional voltage reference.The voltage source adopted is one with the nested Miller compensation,a low-temperature floating,high voltage rejection,low-power consumption and a bandgap reference.Simulation indicates that the order of accuracy of such reference voltage is to 13.2×10^-6/℃,that the voltage rejection at a low frequency is 98dB and that the static working current is 3 μA.

Design of a Filter with Spurious PassBand Suppression Configuration

WANG Yong, CAI Fei, LV Guo-Qiang

. 2010, 23(9): 24.

Abstract ( 1701 )

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This paper designs a parallel-coupled microstrip bandpass filter.It employs half-wave open-ended resonators in view of the 2^nd and the 3^rd harmonic passband responses and introduces transmission zeros so as to have a suppressing effect on the spurious passband at the 2^nd and 3^rdharmonics frequency.The method can increase the suppression by 20 dB and over 10 dB on the spurious passband at the 3^rd and 2^nd harmonic responses,respectively,without major structure modification.

Analysis of the Signal Frequency Spectrum by Graphical Analysis in the Complex Plane

MIAO Yuan-Ben, WANG Jia-Wang, WANG Biao

. 2010, 23(9): 27.

Abstract ( 1587 )

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The method for the signal frequency spectrum analysis by means of graphical analysis in a complex plane is given in the paper.It makes a thorough study of the relationship of the digital frequency to the analog frequency and at the same time gives a detailed explanation of the phenomenon of spectrum aliasing.

A Real-time System Implementation of Multi-level Inverse Wavelet Transformation Based on FPGA

ZHONG Yun-De, SHI Cheng-Xin, MIN Biao

. 2010, 23(9): 30.

Abstract ( 1644 )

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In spite of its many advantages such as higher compression rate,multi-resolution format and progressive transmission shows decoding,JPEG2000 has not been widely used because of its high cost of implementation since it was proposed.This paper presents a solution to the high-speed and real-time hardware of multi-level IDWT based on FPGA in view of the kernel processing module——inverse discrete wavelet transform (IDWT) in JPEG2000 decoding system.Simulation shows that this solution can meet the requirement for real-time processing of continuous input of data.Besides,the system has the advantages of less consumption and lower cost.

Engineering Implementation of the IF Digital Receiver

WANG Hong-Yan, LIU Yong, JIANG Xiao-Jie

. 2010, 23(9): 34.

Abstract ( 1293 )

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This paper presents a method for design of an IF digital receiver and demonstrates its engineering implementation in detail.The design uses software radio technology and adopts a high-speed ADC,FPGA and PCI bus as its hardware structure,enhancing the flexibility and reliability of the system.Experiment indicates that this design is of high value in engineering.

Calculation of the Radiation Pattern of the Reflector Antenna with Distorted Reflector Surface

LI Kai-Tuo, YU Ding

. 2010, 23(9): 38.

Abstract ( 1192 )

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Because of their large size,large reflector antennas tend to be distorted under the influence of an external force,so calculation of the radiation pattern of the reflector antennas with distorted reflector surface is of importance.With distortion of the reflector surface,calculation of the radiation integral becomes complicated.This paper makes use of the surface projection Jacobian to deal with the radiation integral,thus simplifying its mathematic equation.Finally,a comparison of the computing result with the GRASP result is made,showing that the two results are identical.

Design of a Circular Polarization Microstrip Array Antenna

ZHANG Ming-Min, YAN Ze-Hong

. 2010, 23(9): 41.

Abstract ( 1404 )

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A study of a circular polarization microstrip array antenna is made.The emphasis is laid on the method for realization of a high-gain circular polarization array antenna by means of double-fed square elements.Simulation is carried out using the Ansoft HFSS software,and the simulated result shows that over the range of operating frequency,the antenna gain is higher than 13 dB,VSWR is less than 1.3,and both of the E-plane beamwidth and H-plane beamwidth are more than 33°.

Design and Analysis of the OFDM-CPM Communication System

QIAN Zhi-Jun, ZHOU Yuan, GUO Qiang

. 2010, 23(9): 44.

Abstract ( 1593 )

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This paper makes an analysis of the features of the Orthogonal Frequency Division Multiplexing-Continuous Phase Modulation(OFDM-CPM) communication system.A scheme of modulation and demodulation that can be readily implemented in engineering is designed.In the multi-path with white Gaussian noise channel,a comparison in bit error rate(BER) characteristics is made between OFDM-CPM system and OFDM-QPSK system.The impact of modulation index on the OFDM-CPM system BER is studied,and the OFDM-CPM system BER can be decreased using convolutional codes.

Simple Receiver for the LST-CPM System

YANG Yi-Jia, DU Xin-Jun

. 2010, 23(9): 47.

Abstract ( 1413 )

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Increasing attention is paid to Continuous Phase Modulation (CPM) system due to its characteristics of constant amplitude and high spectrum effectiveness in the field of wireless communication,so reducing the decoding complexity of the system is a key topic.In this paper,based on Layered Space Time (LST),a receiver of reduced complexity consisting of Laurent decomposition of CPM signals and MMSE detector is presented.In the low SNR condition,it achieves near-Maximum Likelihood (ML) performance with feasible complexity.Both theoretical derivation and simulated result confirm the effectiveness of the proposed method.

Design and Implementation of the Location Card for the Mine Underground Position System Based on WLAN

FENG Gang, JIANG Lei

. 2010, 23(9): 50.

Abstract ( 1332 )

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The location card for mine underground position system based on WLAN is portable embedded device for mine workers,so it must satisfy the requirements of light weight,small volume,anti-interference and low power consumption.The paper discusses the design and implementation of location card from the aspects of both hardware and software,and puts forward some design methods for its non-functional requirements (anti-interference and low power consumption,etc.).

Design and Application of Read/Write Chip-PicoRead RF of the Contactless IC Card

LIU Wei, XU Hui-Bin

. 2010, 23(9): 58.

Abstract ( 1437 )

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Contactless IC card is a card combining radio frequency identification technology and IC card technology,and card reader is the basic device.PicoRead RF is a contactless card reader launched by Inside Contactless Company.Stable in performance,low in price,and supportive of a variety of protocols,this chip is widely used in the contactless reader devices.This paper gives a particular introduction to the features and working principle of the PicoRead RF chip,and its design and implementation in software,in hope of offering some guidance to readers.

Research on the Simulation Method for IR Daily Characteristics against Clutter Background

ZHAO Can, HUANG Xi

. 2010, 23(9): 60.

Abstract ( 1185 )

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An analysis of the main factors affecting the Infrared Radiation daily Characteristics is made,followed by the establishment of an Infrared character model against clutter Background.An hourly calculation of the surface temperature of some classic clutter Background is made based on the model above.With the temperature obtained,Infrared Daily Characteristics in special situation of clutter Background is simulated.

Numerical Simulation of Thermal Focal Length in Diode Pumped Solid State Lasers

GUO Long-Cheng, GUO Zhen, WANG Shi-Yu, LIU Hai-Qiang, SONG Xiao-Lu, LI Bing-Bin

. 2010, 23(9): 63.

Abstract ( 1411 )

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In the axisymmetrical condition,the temperature distribution of the laser crystal was theoretically analyzed with the pump beam as a standard gauss beam and the heat smoothly distributed,and the thermal focal length is calculated.With different pump power and pump beam radius,the temperature distribution is numerically simulated by ANSYS.The phase distortion of the plane wave through the crystal is numerically calculated.The curve for the variation of the thermal focal length with the radius is plotted.A numerical analysis indicates that the thermal focal length changes with the radius,that the outgoing wave is a non-spherical wave,and that the equivalent concave mirror of thermal lens is aspherical and can not be described by single curvature radius.Finally,a study is made of the effect of pump power and pump beam radius on the thermal focal length.

SIMS Test of Phosphorus in Silicon Wafer

CHEN Mi-Hui, HE Xiu-Kun, MA Nong-Nong, CAO Quan-Xi

. 2010, 23(9): 68.

Abstract ( 1351 )

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Use is made of SIMS (secondary ion mass spectrometry) to test the trace amount of phosphorus in heavy arsenic doping silicon wafers.Pretreatment of the samples and precise control of the equipment significantly shorten the testing time and limit the phosphorus detection to as low a degree as 5×10¹³ cm^-3.Experiments show that the pretreatment of samples have great effect on the results of the test.Surface roughness differs with each other when pretreatment ways vary.And the surface roughness will directly affect the testing time and accuracy.At the same time,by equipment adjustment,the vacuum reaches 1×10^-10 torr,thus greatly decreasing the background noise of sample test and detection limit.

Influence of the Thickness of the Ferroelectric Thin Film on its Phase Transition Properties

YOU Na, ZHANG Xian-Jun, WANG Sheng-Peng

. 2010, 23(9): 71.

Abstract ( 1442 )

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In the change of the thickness of the ferroelectric thin film,a study is made of the properties of phase transition of the ferroelectric thin film based on the transverse field Ising model using the framework of the mean field approximation.A calculation of the phase diagrams and polarizations as well as the Curie temperature of the ferroelectric thin film with different thickness is made by numerical method.Results show that the thickness has sensitive effect on the phase diagrams and the polarizations.However,it has not effect on the Curie temperature.

Study of Wavelet Transformation in Symbol Rate Estimation

MA Xiao-Yu

. 2010, 23(9): 74.

Abstract ( 1669 )

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Wavelet transformation has the characteristic of local microscope,so it is able to capture the instantaneous character of signals.This paper introduces the basic principle of Haar wavelet,and makes an analysis of the wavelet domain character of PSK signals starting with the definition of continuous wavelet transformation.Simulation of the wavelet transformation of QPSK signals in the background of white gauss noise is performed,whose result indicates that wavelet transformation can effectively obtain and extract the information of signals.

Adaptive Rate Control Algorithm Based on FBRM

XU Lei, WANG Sheng-Li, XIE Hui, WANG Li-Li

. 2010, 23(9): 77.

Abstract ( 1674 )

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The paper presents an adaptive rate control algorithm based on the rate feeding back MQ in view of the fact that MQ of the EBCOT takes lots of time and resources.The wavelet subband has a specialty of adaptively choosing Coding Pass to enter MQ,and the feedback control that enters the stream of Coding Pass does not enter MQ coding pass,based on which,cut-off points are located and the pieces of coding pass with no contribution to final code are abandoned.This done,the whole coding efficiency of EBCOT is increased.The algorithm makes no effect on the quality of image compression,but significantly increases the coding efficiency of the whole EBCOT.Experiment indicates that the algorithm can reduce the amount of calculation and storage of MQ in EBCOT,easy to be implemented in hardware.

Algorithm for H.264 Inter-frame Fast Mode Selection

LV Bo, LI Yu-Shan, LIU Yang

. 2010, 23(9): 80.

Abstract ( 1393 )

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To improve the encoding speed of H.264,a fast inter-frame mode selection algorithm is proposed.With image difference as a standard measure of level of image motion detail,the best inter-frame mode is selected directly,so as to avoid the constant calculation of each inter-frame mode and their comparison.Experiment shows that,without much loss of image code rate and PSNR,inters prediction time is reduced by 75% compared with the original algorithm,and D1 image real-time encoding in H.264 is realized.

Adaptive Rate Control Algorithm Based on Rate Pre-allocation

WANG Sheng-Li, WANG Jiao, XU Lei

. 2010, 23(9): 83.

Abstract ( 1368 )

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An algorithm for rate pre-allocation is proposed based on the research on image entropy.Based on a prediction module,an entropy estimate of effective bit-plane is made,and the sum of entropy estimates controls the rate pre-allocation.By pre-allocated rate,MQ controls coding depth and rate-distortion optimal interception.The proposed algorithm can reduce the MQ coding time significantly,which helps hardware implementation.

Application of Improved BP Network Algorithm in Image Recognition

YAO Hui-Juan, LUAN Xiao-Ming

. 2010, 23(9): 86.

Abstract ( 1700 )

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In traditional BP neural network weight is adjusted by steepest gradient descent method and training process could attain error-free result by following the ramp of the error function from the start,but it has some disadvantages such as slow convergence rate of training process and is prone to fall into local minimum.An improved algorithm is proposed in this paper,which makes a combination of momentum gene and adaptive learning rate,thus allowing it to keep network from falling into local minimum and accelerate training speed.Experiment shows that the improved algorithm has higher recognition accuracy rate compared with simple BP algorithm.

Application of Improved Decision Tree Algorithm

WANG Yuan, WANG Tian-Tian

. 2010, 23(9): 89.

Abstract ( 1195 )

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This paper proposes an improved decision tree algorithm with regard to the fact that ID3 algorithm is inclined to multiple sampling,and that subjective factors affect classification in some specific areas.It employs decision tree algorithms to construct decision tree,and marks the subjective and objective properties in classification to perform logic operation.Objective decision information is obtained,and verified by experiment.

Detection and Tracking Algorithm for Moving Object in Video Sequence

LV Li-Juan, CHEN Jian-Chun

. 2010, 23(9): 92.

Abstract ( 1446 )

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This paper presents a detection and tracking algorithm for moving object in video sequence.A combination of the difference and the background subtraction based on codebooks background modeling,the algorithm can have accurate object detection and extraction of the moving object.It can also extract background with the existence of moving foregrounds.A kalman filter is used to predict the moving object's position at the next moment,so that by Camshift tracking algorithm,search and object matching can be made over a smaller range,thus reducing the amount of calculation,saving the searching and matching time and improving the tracking efficiency.Experiment shows that this algorithm is of practical value.

Modified Method for Joint Ranges and DOA's Estimation of Near-Field Sources

LI Shi, LEI Ting

. 2010, 23(9): 96.

Abstract ( 1093 )

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This paper presents a new method for joint estimation of ranges and directions-of arrival (DOA's) of multiple near-field sources without pairing parameters.A new matrix has been obtained from the transformation of the constructed four-order cumulant matrix.The parameters are directly given by the eigenvalues and eigenvectors of the new matrix.Compared with ESPRIT-Like method,the proposed method can achieve automatic pairing.Finally,simulation validates the performance of the proposed method.

Design and Implementation of an Embedded Digital Audio AGC System Based on SOPC

CHEN Yi, CHEN Ming-Yi

. 2010, 23(9): 99.

Abstract ( 1469 )

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This paper presents the implementation of embedded digital audio AGC system based on SOPC with the transplant of the real time operating system RTOS μC/OSⅡ as the running platform of the embedded application software.By adopting a multiparameter AGC method,AGC is realtime processed.The embedded digital audio AGC system with noise restrain ability that can find application in digital studio is designed and implemented.

Design and Implementation of a Medical Endoscopic Imaging System

ZHANG Jun, ZHONG Jian-Dong, WANG Deng-Peng, PAN Xi-Chuan

. 2010, 23(9): 103.

Abstract ( 1203 )

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Medical endoscopic imaging system is the center of endoscopic image information acquisition,processing,storage and transmission.The completeness of its functionality,stability and easy maneuverability plays an important role in the clinical use of endoscopy.This paper designs and implements a digestive endoscope imaging system.In addition to its common features,the system combines secondary lesions image acquisition,the maintenance of typical case library and the method of “WYSIWYG”,thus increasing the efficiency of treatment.A comprehensive test of the system is performed to ensure the completeness of its functionality and its stability.

Insulation Supervision of the Direct Current System Based on the MSP430 Processor

ZHONG Hong-Rui, LUO Jin-Ping, LIN Shu-Guang

. 2010, 23(9): 106.

Abstract ( 1506 )

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The paper first introduces the insulation supervision of direct current system,then explains in detail the principle of balance and unbalance used to measure the insulation resistance,and finally presents the key technology for hardware and software design of the direct current grounded detect system.The practical application shows that this system can detect the insulation resistance of direct current systems with accuracy.With high practicability,the system provides a valid and necessary method for detecting direct current systems grounded.

Study of Landing Control over the Unmanned Helicopter

GUO Shu-Shan, YUAN Suo-Zhong

. 2010, 23(9): 110.

Abstract ( 1144 )

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A trajectory control system based on neural network is introduced.Aiming at the special requirement for the landing of the unmanned helicopter,this paper designs the trajectory of the landing and develops the landing control system by dynamic inverse control method.The error between the model and the real helicopter is compensated by the use of neural network.On the basis of this control system,simulation software is used to perform numerical simulation.

Automatic Inspection System for Fluorescent Magnetic Flaw Detection

LIU Jia

. 2010, 23(9): 113.

Abstract ( 1686 )

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The paper introduces the implementation of the automated inspection system of fluorescent magnetic particle testing.Based on the principle of fluorescent magnetic particle testing,the system controls magnetic particle testing machine and stepper motor with a computer as the central control system.Combined with image processing and machine vision technology,the system makes a detection of the size and defect of the workpiece metal shell.

Oversampling Technology Based on ARM Cortex-M3 Kernel

YAN Ying-Jun, ZHANG Zi-Qiang

. 2010, 23(9): 115.

Abstract ( 1453 )

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This paper introduces implementation of an oversampling technology based on ARM Cortex-M3 kernel.Experiment indicates that oversampling technology can achieve the same sampling effect without external ADC device.The combination of Cortex-M3 kernel and oversampling technology not only reduces the cost,but also improves system's operating rate,reliability and stability.

Application of the Data Warehouse Technique in Aero Service Information Analysis

LI Wei-Bin, YANG Jia-Feng, WANG Bao-Bao

. 2010, 23(9): 118.

Abstract ( 1467 )

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This paper presents a research model of an aero service information system based on the aviation maintenance management information system.This model can be applied to aviation maintenance information on-line analytical processing,and be used in data mining by the decision tree algorithm and association rule algorithm,so that an intelligent analysis of aviation maintenance information can be made.

Multimodal Medical Image Fusion Based on the D-S Evidence Theory

YANG Ling, LIU Jing

. 2010, 23(9): 122.

Abstract ( 1351 )

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Aiming at a multimodal medical image with blurry edges and unclear textures after being fused,this paper proposes a method for image fusion based on D-S evidence theory.Wavelet decomposition is the priority for the image to be fused.In high frequency domain,with the properties of textures and edges as evidences,the property of each point can be obtained through the use of the Dempster evidence composition and judgment regulation,and thus the fusion regulation is determined;in low frequency domain,the fusion regulation based on the district grads is applied.Experiments indicate that edges and textures of the original medical image can be relatively completely reserved with an effectively higher performance,superior to other methods of this kind.

Method for Airport ROI Segmentation Based on LogGabor

WANG Li, WANG Hai-Tao

. 2010, 23(9): 125.

Abstract ( 1072 )

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