A Millimeter-Wave Radar Imaging Mode Combining Transmit Scanning and Receive Digital Beamforming

A millimeter-wave radar imaging mode combining transmit scanning and receive digital beamforming (TSCAN-RDBF) is proposed to solve the problems of strong target covering weak target and multipath interference in the practical application of MIMO mode. In the TSCAN-RDBF mode, spatial filtering is achieved by scanning the space in the transmission stage using a phased array. In the reception stage, the full high-resolution radar image is obtained by compressed sensing of the echo signal at the position of each transmit beam to achieve angle super-resolution within the transmit beam. The effect of MIMO mode and TSCAN-RDBF mode in weak object detection and indoor scene reconstruction are compared in the same millimeter-wave radar system. The experimental results show that the TSCAN-RDBF mode can efficiently detect weak targets with RCS of -82dBsm under interference from targets with RCS of 140dBsm. At the same time, the TSCAN-RDBF mode can effectively suppress multipath interference in the scene.