Design and Simulation of Tunable Phase Shifters Based on Liquid Crystals

Abstract In this article, the use of liquid crystals for three types of tunable phase shifters in planar technology is proposed. Those structures are a microstrip line phase shifter, an access coplanar wave guide phase shifter, and a symmetric stub phase shifter with a liquid crystal cavity. To benefit from liquid crystal anisotropy and thus obtain agility, a bias voltage is applied. The simulated results of a symmetric stub phase shifter are compared with measured data, and good agreement is obtained.