Wideband Transmitarrays based on Anisotropic Unit-Cells for Next Generation sub-THz Applications

This paper presents an anisotropic transmitarray for next-generation applications in the 300-GHz band. First, the proposed three-layer unit-cell is analyzed theoretically to demonstrate its effectiveness in transmission and bandwidth operation. Then, two designs using different manufacturing technologies are synthesized. The first one is based on a standard printed circuit board process to represent a low-cost solution. The second one uses lithography in fused quartz, leveraging a higher fabrication and transmission phase resolutions for more efficient transmitarray design. Based on the two structures, two 40×40-element prototypes are realized considering these two fabrication streams. The low-cost prototype is measured, achieving a peak gain of 32.2 dBi with 31.8% aperture efficiency and a 3-dB gain bandwidth of 55 GHz (19%).