A Symmetric Beam-Phased Array Fed by a Nolen Matrix Using 180° Couplers

Abstract

This letter presents a new microstrip line-phased array using 3 × 3 Nolen matrix - with three inputs and three output ports. For each input port excitation, the signal is divided into three equal magnitudes and unique progressive phase shifts at its output ports. The proposed microwave network is composed of three 180° couplers with two of them having identical coupling factors and two microstrip line-phase shifters. To verify the proposed design concept, a prototype of the feeding network working at 5.8 GHz is designed, fabricated, and measured. Both simulation and measurement results are in good agreement with the theoretical prediction.