Radar Target Rcs Measurement Systems And Microwave Imaging Diagnostic Techniques

This paper presents indoor radar cross-section(RCS) measurement system and 1-D, 2-D, 3-D microwave imaging diagnosis techniques.RCS measurement is necessary to research the electromagnetic scattering properties of radar target as well as to design stealth weapon system. The theory and algorithm of electromagnetic scattering computation can be verified by RCS measurement, moreover, it's difficult to compute electromagnetic scattering of complex objects, but the data can be obtained visually by RCS measurement. Microwave imaging diagnosis technique is useful for identifying and analyzing distribution of target, which can improve the studies of electromagnetic scattering theory. The spatial location and magnitude of scattering centers on complex object can be acquired by microwave imaging, so it effectively helps to enhance the performance of stealth weapon system.This paper mainly consists of three parts:In part one, some essential equipments of RCS measurement system in anechoic chamber are listed, then the operating principle of CW system is described. On the basis of these, some test results of standard and complex objects are given. Finally, for the error of measurement, some potential reasons are analyzed, and the corresponding settlements are presented.In part two, a broad band RCS measurement system, called stepped frequency CW system, is demonstrated. The system transmits stepped frequency signal which is provided by high performance PNA., it can realize the measurement of small RCS target by using fast Fourier transform,software counteraction,range gating,synthetic time-domain peaks. By comparing the test results of two systems, it shows that the precision of stepped frequency CW system is higher, and more information can be obtained.In part three, 1-D,2-D,3-D microwave imaging diagnosis techniques are introduced. At first, it describes the theory of 1-D microwave imaging diagnosis techniques. Basis on 2-D imaging modeling of rotating object, three different algorithms are presented, a effective algorithm of diagnosis has been found by comparing the characteristic of them, and then diagnostic results of complex targets are given. Finally, 3-D microwave imaging diagnosis techniques is presented. The vertical position of scattering centers are given by comparing their phase difference of two phase coherent 2-D images which are obtained by using two antennas with a little change in pitch angle. The measured results are given.All of the systems and techniques have been used in the UAV Special Technique National Defense Technology Key Lab of the Northwest Polytechnic University.