Design And Implementation Of Wide-band Radar Target Simulation System

The simulation system of radar has an important role in the development process of radar system.Hardware-in-the-loop(HWIL) simulation technology can effectively make up for the disadvantages of physical simulation and test.The test process and the electromagnetic environment can be accurately controlled during the simulation.Also the simulation can be made repeatedly.Comprehensive test data can be obtained by the simulation.The radar target simulation is one important part of the RF simulation. It provides necessary simulation and test conditions for the new system radar's investigation, production and maintenance.This thesis studied the method for wide-band radar target echo modeling and simulation according to the need of wide-band radar target HWIL simulation. The coherent target echo of wide-band radar system can be considered as the output of a linear system. The transfer function depends on the target information, including the distance of the target, the elevation and azimuth of the target, the back scattering coefficients and the additional phase shift, the relative velocity of between the radar system and the target and so on.The main content and creative work are summarized as follows:(1)Firstly, the description methods for electromagnetic scattering characteristics of wide-band radar targets are studied in detail. The 1-D geometrical theory of diffraction(GTD) model is used to obtain more accurate electromagnetic scattering characteristics of the target.Secondly, the improved total least squares-rotational invariance technique(TLS-ESPRIT), combined with the orthogonality of signal and noise subspace, is applied to extract the scattering center based on 1-D GTD model.Finally, a typical target is given as an example, to demonstrate the target scattering centers extraction.(2)The wide-band radar target echo is analyzed in theory and modeled, according to the characteristics of wide-band echo. The calculation method for the target echo is studied when the radar transmitting signal is a linear frequency modulation(LFM) signal.Two methods to for wide-band target echo modeling are used:one is based on GTD scattering center model;The other is to divide the target according the radar range cell, extract the equivalent RCS and scattering coefficients in the same range cell, convolve the equivalent scattering coefficients in the range cell with the radar transmitting signal and compose the echoes in different range cells being delayed according to the distance of the range cell.(3)The typical target echo is numerically simulated based on the scattering centers model. Thestatic and the dynamic target echoes are simulated and the high resolution range profile(HRRP) is also given.A certain missile target is also simulated as an example. The back scattering coefficients of each range cell are calculated. Based on the equivalent scattering coefficients in the range cell target echo is calculated.(4)Simulation results for typical targets demonstrate that the HWIL simulation system has a good spurious free dynamic free(SFDR) performance. The SFDR is better than-50 d Bc in 500 MHz bandwidth.