Analysis of Interferometric Millimeter-Wave Target Detection Technology Based on Active Illumination Echoes

In this article, a novel method for interferometric target detection that employs coherent echoes and spatial frequency sampling is proposed. Originating from radio astronomy, interferometric passive microwave imaging has become widely applied for the passive microwave remote sensing of Earth. The proposed technique, termed Interferometric Coherent Echo Detection, is a novel active imaging method that capitalizes on coherent echoes to sample the spatial frequency domain. In comparison with traditional active imaging systems, the proposed approach is characterized by an autonomous transceiver system that operates independently. This system negates the requirement for phase synchronization and eliminates the need for specific modulation techniques to be applied to the emitted waveform. Compared to passive imaging techniques, the technique of interferometric target detection using echoes obtained from active transmission reduces the system’s receiver sensitivity requirements by using transmitter. The detection methodology presented herein is designed to suppress the spatial coherence of the echo by optimizing the positioning of the transmitter. The theoretical derivation and subsequent simulation validation confirm the feasibility of the proposed echo interference measurement technique. Furthermore, an experimental apparatus incorporating automotive radar chips and a Field-Programmable Gate Array (FPGA) successfully identified multiple target points.