Abstract:In the past, people always use planar metal instead of armored target in passive millimeter wave detection, and the detection signal of planar metal and water is very similar, so it is difficult to distinguish these three targets. To solve this problem, started from the basic theory of passive millimeter wave detection, established the target model, deduced the antenna temperature calculation model, simulated the detection signal and found the source of signal differences, summarized and analyzed the roots of the differences. The simulation results demonstrate the validity and feasibility of the conclusion, which provides necessary theoretical support and analytical basis for the study of armored target recognition algorithm.