Near-Field Millimeter-Wave Phased Array Imaging With Compressive Sensing

Phased array technology allows for fast electronic beam steering with high antenna gain for radar imaging systems. Currently, common algorithms mainly concentrate on scenarios where targets are in the far-field zone; however, the beamforming performance will be impaired in the near-field zone. This paper presents a compressive sensing (CS)-based phased array imaging method for near-field applications. A novel data acquisition methodology has been proposed on the basis of near-field focusing techniques. CS measurements are taken by randomly focusing beams in the near-field region. When compared with the far-field imaging approach, the proposed method shows superior performance in the presence of noise and background interference. Moreover, the near-field method can better minimize the grating lobe issues caused by using large antenna element spacing. Finally, we show that the resolving power of CS imaging systems can be affected by target sparsity.