Near-Filed Millimeter Wave SAR Imaging of Multiple Targets with Different Ranges

In this paper, near-field millimeter wave synthetic aperture radar (SAR) imaging of multiple targets with different ranges is demonstrated and its performance is evaluated. The millimeter wave SAR is built using a commercial TI radar with a bandwidth of ~4 GHz (77–81 GHz) and image reconstruction is realized by a matched filter method. The experimental results show that the image reconstructed at a specific range plane is easily affected by the targets at nearby range planes, especially when the multiple targets are placed within a range resolution unit. Besides, compared with the case of multiple targets without overlapping along the radar line of sight, the interference between targets of different ranges becomes more serious on the radar image when multiple targets are placed with partial overlapping.