Steerable Reflectarray Using Tunable Height Dielectric For High-Power Applications

Abstract

A reconfigurable reflectarray using a tunable height dielectric was designed for high-power applications. Each unit cell consists of a spiral slot etched into a metal sheet. The unit cell was able to support both linear and circular polarization without a change in the phase response. The design was able to achieve 330 degrees of phase range with a loss of 0.3 dB. Unlike other architectures that use semiconductor devices such as PIN diodes for tuning, the proposed mechanical reconfiguration of the dielectric layer beneath the slot enables high-power applications in radar and communication. A full-wave model was constructed for 10x0 10?0 square aperture consisting of 20x20 elements. The simulated reflectarray was able to steer the beam from -30° to 30° with a 2.2 dB drop in the peak gain. The antenna exhibited a peak gain of 24.6 dB. The axial ratio was below 1.8 dB for both left-hand and right-hand circular polarizations at 20 GHz. The array axial ratio bandwidth was 12.5%.