Design of a wideband Rotman lens with dummy ports for wide-scan phased array applications

Abstract

A wide-band wide-scan phased array is investigated by utilizing the beamforming network that is based on a microstrip Rotman lens. A wide beam scanning capability of ±40° for the frequency range 8-12 GHz is demonstrated. The most crucial part is to design a wide beam scanning rotman lens in conjunction-with a good impedance matching over the entire frequency band. To do so, dummy ports are placed between inputs ports and output ports of Rotman lens as mutual coupling between ports are reduced significantly which results in improving the performance of Rotman lens.