Antenna And Conditioning Circuit Design Of Electromagnetic Pulse Acquisition System

Electromagnetic Pulse(Emp)is widely found in nature and has many applications in industry,agriculture,medicine and military.EMP acquisition technology is the basic premise to know and use it.Several domestic research institutions and universities,such as Northwest Institute of Nuclear Technology,Chinese Academy of Engineering Physics,Ordnance Engineering College,PLA University of Science and Technology,etc,have done some researches.Foreign institutions such as the United States institute of Metrology and Standardization,Korea Institute of Metrology also have corresponding research.EMP is a kind of transient high-intensity signal,and its measurement system should have the characteristics of wide frequency band,fast response time and wide dynamic range.In this paper,the following researches are carried out based on these requirements:First,the waveform standards and characteristics of electromagnetic pulses are analyzed,and the front-end antenna form of the near-field electromagnetic field acquisition system is determined based on the basic principle of the antenna and the system function of the acquisition system.Then the signal conditioning part including the optical transmitter(hardware integration circuit)was developed to improve the anti-interference ability of the acquisition system during the transmission process;and for the acquisition of near-field electromagnetic pulse signals,a set of multi-channel high-speed data was constructed The acquisition equipment,composed of the above-mentioned parts,constitutes a complete nearfield electromagnetic pulse electromagnetic field acquisition system.Secondly,the calibration equipment and calibration methods for the near-field electromagnetic pulse electromagnetic field acquisition system are researched and designed.After the completion of the design,the calibration coefficient,frequency response and dynamic range of the acquisition system are calibrated,and the cost of calibration results are reduced under the premise of ensuring the accuracy of the calibration results.Finally,the high-sensitivity magnetic field antenna and antenna conditioning circuit of the differential structure are redesigned for the direction finding application of the far-field electromagnetic pulse acquisition system.The feasibility of the differential structure is demonstrated through circuit simulation and testing.Then,the direction finding algorithm and accuracy of the direction finding antenna structure of the two-dimensional/three-dimensional structure are analyzed,and the direction finding accuracy is verified by the electromagnetic simulation software CST.The thesis has developed a set of near-field electromagnetic pulse acquisition system,the dynamic range of electric field measurement can reach 3 V?m-5 k V/m,the bandwidth of 100Hz-50 MHz;the dynamic range of magnetic field measurement can reach 1 A/m-10 k A/m,frequency 100 Hz-10 MHz,by cooperating with the conditioning circuits in different optical transmitters,high-sensitivity and low-sensitivity signal measurement can be achieved.For direction finding applications,a set of far-field electromagnetic pulse acquisition system is also designed,including a high-sensitivity magnetic field measurement antenna with a differential structure and corresponding conditioning circuits.