Research And Implementation Of Data Acquisition Technology Of Terahertz Array Scanning Imaging System

Terahertz array scanning imaging system can achieve high resolution imaging of near-field targets,and can be used in the field of military reconnaissance,missile guidance,safety inspection,etc.However,the raw signal of radar imaging system with array scanning usually has high data rate,this makes it difficult to realize the data acquisition technology of terahertz array scanning imaging system.This paper studied the design of the system,the method of data compression and extraction filtering,data acquisition technology,the test and the simulation of the system.Aiming at the design of terahertz array scanning imaging system,this paper analyzes the terahertz source related technology,sending and receiving antenna array related technology.And this paper determine the main technical indicators of the system such as the working frequency,frequency modulation mode and frequency modulation cycle.After that,based on the above analysis,this paper analyzes the function of the data acquisition subsystem,and determines the key issues to solve the data acquisition technology,and finally completes the hardware selection.Aiming at the method of data compression and extraction filtering,this paper analyzes the design idea of the traditional multiphase extraction filter,and summarizes the design principles of filtering and parallel processing.Then this paper derived the base-2 FFT algorithm.In the end,the method of data compression extraction filtering based on the base-2 FFT algorithm and the traditional multiphase extraction filter design principle is proposed,and this paper designed two kinds of hardware implementation structures considering the hardware resources and the processing speed.Finally,we completed the simulation verification and performance analysis of the method.Aiming at the design and implementation of the hardware,this paper studied and solved the problem of the system configuration circuit of the FPGA and the DSP and the problem of peripheral expansion circuit of the data acquisition subsystem,and mainly studied and solved the high-speed interconnection between the FPGA and the DSP.Aiming at the program design and analysis of hardware circuit,this paper focuses on the programming of the module of multichannel high-speed data acquisition,the module of offline storage,the module of the high-speed interconnection between the FPGA and the DSP with hardware description language,after that,the above modules are analyzed by means of actual measurement or simulation.