Near-Field BP Imaging Algorithm Based on Antenna Pattern Gain Compensation

Ultra-wideband MIMO radar can provide precise range and azimuth information of multiple targets and is widely applied in military, aviation, transportation, and other fields. However, the antenna radiates electromagnetic energy in a specific direction, and the coverage area in azimuth is limited. Compared with targets in the antenna's main lobe, the large-angle targets outside the antenna's main lobe scatter weaker radar echoes. Therefore, weak targets will be overshadowed by strong targets. This paper proposes a near-field BP algorithm based on antenna radiation patterns compensation. The antenna radiation pattern was measured in the anechoic chamber. Then, digital beamforming technology was utilized to construct a gain compensation matrix achieving radar data compensation from different directions. Experimental results showed that the proposed algorithm effectively enhanced the energy of large-angle targets in multi-target scenes.