Millimeter-Wave Imaging With Optimized Sparse Periodic Array for Short-Range Applications

摘要

This paper presents a multiple-input–multiple-output imaging system on the basis of a hybrid concept with synthetic aperture radar and digital beam forming. By moving a multistatic linear array perpendicularly to the array dimension, a 2-D aperture is sampled. The scope of application is concealed weapon detection in conjunction with the imaging of humans and, alternatively, nondestructive testing (NDT). The frequency range of 75–90 GHz was chosen because of the inherent high lateral resolution. For NDT, it seems to be a good compromise between lateral resolution and penetration depth as well. A moderate number of transmit and receive channels are achieved by a sparse periodic array (SPA) design. Since this is a far-field approach, ambiguities are not well suppressed in the near-field point spread function of the sparse array. An extension of the SPA concept for short-range applications on the basis of an optimized array design and an optimized beamforming algorithm is presented in this paper.