Phase error minimization by refocusing Rotman lens

In this paper, we propose a refocusing method for minimizing phase errors of Rotman lenses. The method is based on finding the optimal α, F, and γ minimizing the phase errors by moving off-axis focal points along a beam curve. It ensures additional phase error reduction without significant changes of beam and array curve shapes. Simulation results show considerably improved phase performance when this method is applied to Rotman lenses with the conventional circular, elliptical, and optimized beam curves.