K-band substrate integrated waveguide variable phase shifter

Abstract

A substrate integrated waveguide (SIW) variable phase shifter for K-band applications is presented that can be straightforwardly integrated with other SIW antenna feed circuitry. Biasing of two varactor diodes provides continuous control of the phase shift. The results demonstrate that the proposed structure has a wide phase tuning range, flat insertion loss and low reflection coefficient over a wide frequency band. Experimental results confirm that the phase can be shifted by up to 200 degrees at one frequency and by about 140 degrees for the rest of the band. Insertion losses are measured at 4 dB, and the return loss is better than 10 dB.Index Terms-phase shifter, substrate integrated waveguide, feed network, varactor diode.I.