High-resolution Near-field Imaging with a Microwave Photonic Broadband Array Radar

High-resolution imaging of near field targets is experimentally demonstrated using a broadband microwave photonic array radar that is implemented by photonic frequency quadrupling and de-chirping. A scanning time delay (STD) compensated digital beam forming (DBF) method is adopted to deal with the beam squint and broadening problem in broadband radar imaging. In the experiment, a 1×16 microwave photonic array radar having a bandwidth of 8 GHz is implemented. By using the STD-compensated DBF method, high-resolution imaging of near-field targets is achieved with obvious suppression of grating lobes and accurate beam correction.