Phase Change Material Based Reconfigurable Transmitarray: a Feasibility Study

In this paper, we present the design of a reconfigurable transmitarray operating in the D-band (110 – 170 GHz). The transmitarray unit cell has a relatively simple structure with three metal layers and two quartz dielectric substrates. The active transmitting patch of the unit cell ensures a 1-bit phase shift resolution by alternating the states of two innovative switches. Here, we overcome the small dimensions challenge in the D-band by introducing compact switches that are compatible with the dimensions of the proposed unit cell. The switches are made of phase change materials (PCM) that alternate between the amorphous and the crystalline states under the effect of heat. We present a full-wave simulation of the unit cell, which shows an insertion loss that is below 1.5 dB over a relative frequency band of 27%. Furthermore, we synthesize a 16×16 elements transmitarray using an in-house MATLAB tool and compare its theoretical results to a full-wave HFSS simulation. The outcome shows that by integrating the proposed switches into the unit cell, the designed transmitarray can achieve promising reconfiguration results in the D-band.