Reducing Cross-Target Products in Thinned Antenna Arrays using Nonlinear Processing

Antenna array thinning by nonlinear multiplicative processing of subarray signals is highly efficient. It allows thinning rates of up to 90% and is, therefore, very profitable for phased or digital beamforming radar arrays to save significantly on the cost of the antenna elements. However, thinning by multiplicative processing does not come without problems, such as false responses in complex multiple-target situations due to cross-target product terms. The reasons for the occurrence of these ghost targets will be outlined in this paper and a new method to counteract them will be presented. Measurements carried out at 77 GHz are consulted to assess the applicability and the benefit of the proposed method to high resolution radar.