A mmWave Transmitarray with Patch Array Feed

This paper introduces a design method of transmitarray antennas (TAAs) with a small patch array feed. The transmitarray element consisting of two meshed triple-circle rings is studied and analyzed to realize a large transmission phase range of 285° by tuning only the radius of the inner ring. To validate the design method, a TAA of size less than 5×5 λ
0
²
is designed at 38.5 GHz. Simulated results show that the proposed TAA exhibits a high gain of 20.85 dBi at 38.5 GHz while maintaining a gain ripple of less than ± 0.5 dB from 37 to 40 GHz, indicating it is a good antenna candidate for mm-wave applications.