Microstrip Array Antenna with Liquid Crystals Loaded Phase Shifter

A novel phase shifter loaded with LC for operation in the microwave band has been proposed and its application to array antenna is demonstrated experimentally. The phase shifting operation is based on the anisotropy of dielectric permittivity of the liquid crystal caused by the change of applied electric field. As an application of such LC loaded phase shifter, we utilized the phase shifter as a means for electrically controlling the phase of microwave signal fed to a two-element array antenna comprised of two microstrip antennas that was designed for operating at 20-GHz-band. We have confirmed that the radiation directivity of the array antenna can be controlled by the applied bias voltage.