Table of Content

25 October 2019, Volume 39 Issue 5

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Research on Calibration Technology for Amplitude and Phase #br# Characteristics of Large Double Reflector Compact Field

MA Yong-guang；YANG Jin-tao；WU Xiang；HE Xin；HUANG Cheng-zu；HUANG Jian-ling

2019, 39(5):  1-4.  doi:10.12060/j.issn.1000-7202.2019.05.01

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The compact field is the key device for antenna and target RCS testing.It can calibrate the spherical wave from the feed to a quasi-planar wave at close range.In order to evaluate whether the electromagnetic wave distribution generated in the quite zone of the compact field conforms to the quasi-planar wave characteristics,it is necessary to build a high-performance microwave amplitude-phase transmitting and receiving system and a large-scale multi-degree-of-freedom high-precision scanning system on site.In this paper,the performance calibration requirements of a large double reflector compact field are taken as an example.From the aspects of on-site measurement of amplitude and phase system construction,large-scale complex scanning system design,and on-site measurement implementation,the related technologies of field calibration of compact field quite zone performance are analyzed in detail.The measured results show that the calibration system built on site meets the performance requirements of the long-distance large double-reflection surfacecompact field quiet zone,and the values of each test parameter meet the design requirements of the compact field.

Research on Interference Suppression Algorithm based on #br# Bispectrum for eLORAN Receiver

ZENG Ting；HUA Yu；YAN Bao-rong

2019, 39(5):  5-11.  doi:10.12060/j.issn.1000-7202.2019.05.02

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In order to improve the performance of eLORAN navigation and timing receiver,such as enhancing the capability of interference and noise suppression,an interference suppression algorithm based on bispectrum for adaptive filtering was proposed.Using bispectrum method,the additive Gaussian white noise can be suppressed and the interference can be detected,then coefficient of the adaptive filter is updated by the detected signal,and finally interference can be eliminated. The theoretical analysis and experiment results show that the interference with additive Gaussian white noise can be well detected and eliminated,especially in the case of strong noise.The interference suppression problem of eLORAN receiver in strong noise can be solved with this method.

Research and Improvement of Factors Affecting Temperature #br# Coefficient of Rubidium Frequency Standard

ZHANG Jun；WANG Shi-wei；GUO Yong-gang；LU Fang；YANG Wei；SHI Fu-cheng

2019, 39(5):  12-18.  doi:10.12060/j.issn.1000-7202.2019.05.03

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The high-performance passive Rubidium atomic frequency standard(RAFS)is mainly used in special fields such as extraterrestrial environment,Stability and accuracy of RAFS are two keys technologies for satellite positioning.The RAFS Stability includes short-term stability and long-term stability,while the long-term stability is mainly determined by the temperature coefficient.Therefore,The aim of this paper is to improve the temperature coefficient of RAFS,by analyzing the main factors affecting the temperature coefficient of RAFS,in this paper,zero temperature coefficient contour diagram optimization method and zero optical frequency shift lamp excitation voltage optimization method are proposed,and the temperature coefficient of physical package is optimized by improving the thermal design of the physical package,Finally,The temperature coefficient and long-term stability of RAFS was tested and the temperature coefficient is -2E-14/℃ and the frequency stability in 10⁵ is 5.52E-15.Experiment results verify these ways that can really improve temperature coefficient of physics package.

Generation and Maintenance of Local Time & Frequency Standard

YANG Fan；YANG Jun；ZHANG Ran

2019, 39(5):  19-22.  doi:10.12060/j.issn.1000-7202.2019.05.04

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In recent years,time-keeping ability of the local coordination time UTC(BIRM) improving steadily.Up to now,the relative frequency deviation between UTC(BIRM) and UTC is better than 1E-15,the time deviation is better than 16ns.In this paper,the composition of time-keeping system,local frequency steering and master-backup time synchronization technology,and the research of TA(BIRM) algorithm are introduced briefly.

Research and Realization of Vector Signal Modulation Quality Analysis

ZHANG Guo-zhu

2019, 39(5):  23-26.  doi:10.12060/j.issn.1000-7202.2019.05.05

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In many practical application systems such as digital mobile communication system,effective measurement of modulated signal quality is helpful to find the main reason of signal distortion as well as the potential errors in system designing.In this paper,the significations of some parameters,like EVM,and the processes of vector signal analysis are roundly analyzed.The importance of compensating the affection brought up by magnitude and phase distortion is also discussed.This paper realizes a vector signal analysis software according to the signal analysis model,which can be easily embedded in other application systems for different actual needs.

Design of (0.1~1.8)GHz SiGe HBT Ultra Broadband Low Noise Amplifier Circuit

WEI Zheng-hua；YE Xiao-lan；MENG Yang；XIAO Liao-liang

2019, 39(5):  27-32.  doi:10.12060/j.issn.1000-7202.2019.05.06

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In this paper,a small low-power ultra-wideband Low Noise Amplifier(LNA)that can work at(0.1~1.8)GHz was designed with chip of SiGe material.The LNA adopts the structure of two-stage amplifier and negative feedback method to achieve broadband matching.The resistor of small value was used to improve circuit stability.The size of LNA was 35mm×15mm.The measured results showed that when the LNA was working at room temperature,the operating frequency was(0.1~1.8)GHz,the gain reached 30dB,the noise figure was less than 0.82dB,the gain flatness was less than 0.5dB,the input and output return losses were less than -10dB,and the DC power consumption of the circuit was 41.8mW.When the LNA was working at the temperature of -40℃,the gain reached 32dB,the flatness of the gain and the input and output return losses were basically unchanged,and the noise figure was lower than 0.69dB.The feasibility of method proposed in the paper to calculate S parameters of SiGe amplifier at the temperature of -40℃ was verified.

Research on Hign Precision Time Frequency Synchronization #br# based on Optical Fiber Double Loop Network

WANG Peng；LI Shi-guang；DANG Ming-zhao；MAO Xin-kai

2019, 39(5):  33-37.  doi:10.12060/j.issn.1000-7202.2019.05.07

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This paper introduces a kind of double loop network based on optical fiber technology in the time and frequency synchronization technology design method.In the light of the problem of how to obtain hign-precision synchronization index when the time frequency equipment is used in coordination ,a design is proposed.Using beidou /GPS/GLONASS as the system time source,the synchronization accuracy of the system is better than 5E-13,and the frequency stability is better than 5E-13@1d.With the TOD+1PPS output by UTC(BIRMM)as the time source of the system,the synchronization accuracy of this system is better than 4E-13 and the frequency stability is better than 6E-14@1d.This method proposed in this paper is simple in principle,the system can be cut according to the actual use.The cost is low relative to TWSTFT and other means.It is suitable for spreading in time frequency synchronization field.

A Novel Transmission Scheme of HF Time Signals based on #br# Spread Spectrum System and its Feasibility Analysis

YUAN Jiang-bin；LI Shi-feng；YAN Wen-he；YANG Chao-zhong；HU Zhao-peng

2019, 39(5):  38-43.  doi:10.12060/j.issn.1000-7202.2019.05.08

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The application of spread spectrum signal in HF time service system will help to improve the quality of time service.Considering the complexity of HF channel and the limitation of system bandwidth,this paper proposes a novel scheme to transmit HF time signal based on the relative time interval between two spread spectrum signals,and analyses its feasibility.The basic technical ideas of the scheme is expounded,and then theoretical analysis is carried out to verify that compared with the conventional scheme,the proposed scheme can significantly reduce the probability of the time signal detection error of the receiver.Compared with the conventional scheme,the proposed scheme is better realized to coordinate the compatible transmission of the two HF time signals of UTC and UT1,and provide an effective way for the further research of HF time signal modulation technology based on spread spectrum system.

Study on Digital Phase-Locked Loop in the Time and Frequency System

WANG Peng-yu；YANG Zhi-gang；ZHENG Li-li

2019, 39(5):  44-50.  doi:10.12060/j.issn.1000-7202.2019.05.09

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The construction of the external 1PPS/10MHz disciplined Rubidium/Crystal Oscillator by digital 2/3 order phase-locked loop is described in this paper.The Simulation model of frequency standard component is presented,and some key problems about PLL and digital quantitative are analyzed.The parameters set method and simulation result are showed.The hardware design is completed and the testing result verify the correctness of the simulation model.

Ground Wire Current Automatic Compensation Method for Ground Wire Disturbance

WU Shi-qing；WANG Bin；JIN Hai-bin；LI Xiao-zhou

2019, 39(5):  51-58.  doi:10.12060/j.issn.1000-7202.2019.05.10

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This study analyzes the main causes and ways of ground wire interference and points out several measures to suppress ground wire interference.At the same time,in order to solve the problem that diffence mode voltage formed by the ground wire current through the ground wire impedance has an influence on the high-precision measurement performance,a solution based on the ground wire current automatic compensation technology is proposed.With this technical solution,the direct current and the clutter noise current flowing through the ground wire can be automatically compensated to zero,even if the ground wire has DC resistance and AC impedance.And thereby the accuracy of system signal can be improved.

Driver Architecture Design and Performance Analysis of the #br# Normal Closed Electromagnetic Brake

LI Xiao-kun；DONG Fang；XU Bao-yu

2019, 39(5):  59-64.  doi:10.12060/j.issn.1000-7202.2019.05.11

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Aiming at high energy-consuming,low braking force density,serious excitation coil heating shortages of the normal closed electromagnetic brake,attempting to introduce permanent magnet into the electromagnetic driving unit,a new electromagnetic drive mechanism with hybrid electromagnets made of permanent and electromagnet is designed.Combined with the finite element analyze software,the finite element method was applied to analyze magnetic flux density distribution and analyze influence factors on electromagnetic force,the factors includes the cross section shape of permanent shape,excitation coil current,air gap.It was found that high coupling performance of electromagnetic field and permanent magnetic field,the rapid electromagnetic force grow with current increasing and decreasing of gas gap distance,under the same condition,Electromagnetic Driving Structure with L-shaped Permanent Magnet produce a high suction,It has guiding significance for lightweight research of electromagnetic brake.

Research on Photoelectric Module Test Technology of Infrared Earth Sensor

SUN Xiang-ping；ZHAO Hui；LI Yan

2019, 39(5):  65-70.  doi:10.12060/j.issn.1000-7202.2019.05.12

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In the design process of conical scanning infrared earth sensor,based on embedded SoC technology,a realization method of ground test system for small volume special photoelectric components is proposed,which can accurately measure the amplitude,frequency and dynamic frequency of grating signal and reference signal in conical scanning infrared earth sensor.The composition and working principle of the system are introduced,and the accurate measurement method of the amplitude and frequency of unstable grating signal is discussed.

Design of Auto Tracking Smart Car based on CCD

SI Kai-bo；HUANG Jian；LV Lin-tao

2019, 39(5):  71-75.  doi:10.12060/j.issn.1000-7202.2019.05.13

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]In order to realize the automatic line inspection of the car,a CCD camera is used to identify the runway of different colors,and the black line is selected in the test.The CCD has 128×1 pixels and can collect 128 linear array data at a time.it can be converted to 128 8-bit binary numbers,which are output through A/D interface and connected with STM32 microprocessor.The software is used to collect and process the data.The median algorithm is used to find the edges on both sides of the black line and determine the center of the black line.The offset between the center of the car and the center of the black line is calculated to control whether the car turns left,right or straight.The encoder is used to measure the speed of the wheels and the speed PID algorithm is used to control the driving of the car in order to realize the automatic line patrol.The test results show that the CCD line-patrolling intelligent vehicle can realize the function of automatic line-patrolling.It can not only automatically track black lines,but also track lines of other colors,which improves the speed of the cars line-patrolling.It provides a new method and a new idea for the automatic line-following car.

In-situ Calibration Technique for Satellite Magnetic Field Exploration Load

ZHAI Jing-jing；LI Xiang；ZHANG Hai-bo

2019, 39(5):  81-85.  doi:10.12060/j.issn.1000-7202.2019.05.15

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A in-situ calibration technology for satellite magnetic field exploration is studied in this paper,a splited magnetic coil,non magnetic scaffold were designed too.By using this technology,the satellite magnetic field detection load is tested and calibrated at various stages,such as satellite testing,before launching,and so on,which improves the reliability of magnetic load test data,and ensure the effectiveness of the scientific experiment.This calibration technique has been applied to China Seismo-Electro magnetic Satellite(CSES),the first domestic satellite for electromagnetic science experiment in near Earth orbit,and has achieved good results.

Analysis of the Regulations and Development Trends of Metrology Industry

WU Qian；JIANG Xiao-yong；ZHANG Bo；YOU Lang

2019, 39(5):  86-89.  doi:10.12060/j.issn.1000-7202.2019.05.16

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Metrology is an activity to achieve unity of units,accurate and reliable value,which is related to national security,national economy and peoples livelihood.In order to enhance metrology ability and seize the new opportunity of Metrology development,this article carries on the research from the trade policy,the measurement development trndency and so on，it can provide reference for people engaged in metrology management and technical research.

Exploring Scientific Measurement Management Methods to Consolidate the#br# Foundation of Enterprise Development

LEI lei；WANG Zhe

2019, 39(5):  90-92.  doi:10.12060/j.issn.1000-7202.2019.05.17

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As an indispensable technological basis,measurement is an important component of the core competence of enterprises,an important support for scientific and technological innovation,and plays an important basic supporting role for the development of enterprises.Metrological scientific research is the main way for innovation of metrological science and technology and continuous improvement of metrological guarantee ability.This paper introduces the management experience of metrological research projects and puts forward some ideas for further promoting metrological research work.

Practice of Confidentiality Supervision and Inspection in Testing and Calibration Laboratory

ZHOU Ye；YANG Qi；WANG Jing；LIU Xiao-li

2019, 39(5):  93-96.  doi:10.12060/j.issn.1000-7202.2019.05.18

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According to the confidentiality inspection requirements of latest qualification standard,we propose a confidentiality supervision and inspection system that is basing on risk analysis and taking risk control as the core.In addition,we propose a confidentiality supervision and inspection pyramid model and a designing method of all kinds of confidentiality inspection that can guide the work of confidentiality supervision and inspection of testing and calibration laborafory.