Compressed Sensing Digital MIMO Radar Using a Non-Uniformly Spaced SIW Sparse Receiver Array

A compressed sensing (CS) digital radar system based on a sparse array design is proposed for use in automotive collision-avoidance applications. The proof-of-concept radar system offers an enlarged antenna aperture, employing fewer elements and can distinguish targets at an angular separation of only 2 degrees for a bandwidth of 6.25%. This resolution is made possible using a multiple-input multiple-output (MIMO) configuration from the original sparse array which was implemented and tested using substrate integrated waveguide (SIW) technology. More specifically, the total aperture size (of the effective virtual receiver array) is $23.5\lambda $ which is equivalent to a uniform-linear array (ULA) having 48 elements spaced at $0.5\lambda $ apart. However, the total number of elements is 32. This defines a cost-effective setup offering a reduction of 16 elements which accounts for a 33% reduction in the number of required channels for the SIW array. Also, the radar exploits sparse-reconstruction techniques for target detection. Results of the simulations and measurements show that the performance of the proposed SIW antenna and experimentally verified radar system can offer competitive high-resolution detection when compared to other findings in the literature and to the best knowledge of the authors, no similar antenna and radar system implementation has been designed and experimentally verified.