Analysis, Rigorous Design, and Characterization of a Three-Layer Anisotropic Transmitarray at 300 GHz

A novel approach for studying and designing low-cost anisotropic transmitarrays (TAs) at sub-THz frequencies is presented here. The array comprises three metal layers and two interleaved dielectric spacers. A four-port equivalent circuit model is derived to accurately model the anisotropic behavior of the unit cell (UC). The analysis proves theoretically that nearly perfect transmission and complete phase control can be achieved at the same time. A systematic procedure optimizing the admittance tensor of the inner layer is described for the UC design. A 3 bit TA antenna at 300 GHz is fabricated using a standard printed circuit board (PCB) process. The measured results demonstrate that the design methodology is effective even under strict technological constraints. The antenna achieves a peak gain of 32.2 dBi with 36.5% aperture efficiency and 70.4 GHz of 3 dB bandwidth.