Design of switched-line phase shifters with constant phase shift using CRLH TL

Abstract

90° and 180°-switched-line phase shifters using composite right/left handed transmission line (CRLH TL) are presented. To achieve a relatively constant phase shift over a large bandwidth, CRLH TLs implemented using lumped elements and right-handed transmission lines (RH TLs) are used as the reference and delay arms, respectively, of the phase shifters. Computer simulation is used to study and design the phase shifters. The phase shifters are also fabricated and measured to verify the simulation results. For comparison, traditional 90° and 180°-switched-line phase shifters are also designed and simulated. Simulation and measurement results show that, the proposed phase shifters have a constant phase shift, a high return loss and a low insertion loss across the operating frequency band.