Design of 6-18 GHz wideband phase shifters using radial stubs

Abstract

A 6-18 GHz wideband phase shifter is proposed. This phase shifter consists of one Lange coupler, four radial stubs, and four switching diodes and bias circuits. Wideband phase shifting was achieved using two different pairs of radial stubs as the reflective loads of the Lange coupler. Four phase shifters of 11.25, 22.5, 45, and 90 degrees were fabricated and tested. Over the frequency band of 6-18 GHz, the measured maximum phase errors were +/- 2.2, 2.2, 3.6, and 5.5 degrees for the 11.25, 22.5, 45, and 90 degrees phase shifters, respectively.