远场RCS的精确测试方法研究

Study on Accurate Radar Cross Section Measurement in Farfield

传统的微波暗室远场雷达散射截面积(RCS)测量方法是采用点频测试,对低RCS目标,测试系统中需添置对消系统,使暗室背景再下降20 dB以上,才能更准确地检测目标。该方案的缺陷是被测件正后方的暗室后墙反射产生阴影,无法进行对消,而且往往对消系统稳定性较差。文中提出的另一种方法,即RCS的扫频测试方法,通过适当的设置,可得到非常高的精度,而且测试系统简单,省去了复杂的手工暗室对消系统,信息量大。

Traditional method of indoor RCS measurement is the single frequency （ CW ） method. For low backscattering target measurement, a cancelling system is introduced in the testing system to get more accurate result, which reduced more than 20 dB of chamber background level. But there exists some error in the above scheme： the shadowing of target can＇t be compensated, and the compensation system becomes easily unstable. Another scheme is introduced in this paper, that is analyzing testing data in time-domain with FFI＇ by frequency sweeping measurement, and by proper setting, very accarated result can be obtained. The new method has only a simple frame and can get more information, without complex manual adjusting system, such as chamber background cancelling system.