Design and Fabrication of a Liquid Crystal-Based 94 GHZ 360° Phase Shifter for Reflectarray Antennas

Abstract

In this work, we propose a liquid crystal (LC)-based double-dipole phase shifter. By manipulating the electric field, we change the resonant frequency and phase of the electromagnetic wave by deflecting the orientation of LC molecules. We made the LC-based device with a 30 × 30 array of two parallel unequal dipoles on a Quartz substrate. The substrate has an area and thickness of 4 × 4 cm 2 and 480 µm, respectively. The experimental results show that the phase shift of 0 • -385.4 • is achieved at 94 GHz by changing the applied bias voltage on the LC layer from 0 V to 8.4 V. The phase shift is greater than 360 • in the range 91.75-94.85 GHz. When the LC molecules are most significantly affected by the electric field, the maximum precision of phase shift is 4.08 • with a bias voltage of 2 mV.