内场RCS测试环境中误差的消减方法研究

Investigation on Reducing Environment Errors in Indoor RCS Measurement

目标散射截面的测量对雷达目标识别、微波成像等研究领域至关重要;在简述目标RCS测量原理的基础上,对内场RCS测试中的环境误差来源进行了分析,重点研究了地面回波、收发天线之间耦合及暗室侧壁和后墙反射三种误差源的产生机理,并提出了合理的解决方法,即在测试端和转台之间放置隔离吸收屏来减小地面的杂波,在收发天线之间添加吸波材料及时域对消来减小天线间的耦合,以及采用时域门的方法去除侧壁及后墙的反射。对提出的方法在微波暗室内进行了实验验证,通过测量标准金属球的RCS,说明了经过环境误差的消减,测试精度提高1.5 dB。

Measuring radar cross section （RCS） of target is very important for radar target recognition and radar imaging. Based on the principle of RCS measurement, the mechanism of errors generating from the ground is mainly discussed, the coupling of transmitting and receiving antennas, and the multi-path reflections from ceiling and walls are studied. An error-lesse- ning method is put forward that is setting isolation absorbing screen between the testing port and turntable to remove the echo from the ground. Some absorbed materials are laid between transmitting antenna and receiving antenna and time domain coun- teraction to avoid antenna coupling. A time-gating function is adoped to eliminate the multi-path reflection from ceiling and walls. Through measuring the RCS of sphere, the interference from testing environment can be reduced by 1.5 dB via getting rid of error produced by surroundings.