Multiplicatively processed antenna arrays for DBF radar applications

Nonlinear multiplicative processing of receiving antenna arrays enables a significant reduction of elements (i.e. thinning), which becomes increasingly important for large digital beamforming (DBF) arrays. In the paper, several (conventional and multiplicative) array configurations are investigated experimentally with respect to DBF radar applications. Radar measurements were carried out at 5.5 GHz and 77 GHz using a flexible synthetic aperture set-up. The results from the multiplicative systems are compared with those obtained with conventional (fully filled) arrays with regard to imaging performance. Multiplicative systems allow thinning rates of the order of 80%, with minor degradations in image quality. Tolerance simulations indicate a higher sensitivity of multiplicative systems in the presence of amplitude and phase errors.