Measurement-based delay-and-sum signal processing for linear antenna arrays

The design of a delay-and-sum beamformer based on measured data is presented in this paper. Traditionally the weighting of a delay-and-sum beamformer is designed based on an idealized signal model, with specifications on the beam pattern in terms of the beam width and the sidelobe level (SLL). The goal is a trade-off between resolution and the ability to detect targets with a certain dynamic range. In this work we propose an approach to the optimization of a delay-and-sum beamformer with the same goal in mind however not based on the ideal signal model, but based on measured data. Being a measurement-based method even effects of non-idealities that are not part of the ideal signal model such as mutual coupling can be suppressed. The proposed approach is validated in simulations for a 77-GHz 36-elements non-uniform frequency-modulated continuous-wave radar array.