A 220 GHz High-Gain Low-Cost Slot Array Antenna With Integrated Fabry–Perot Cavity

This letter presents a 220 GHz planar high-gain slot array (SA) antenna with an integrated Fabry–Perot cavity (FPC). The sophisticated SA is fabricated by low-cost printed-circuit-board (PCB) technology, and an FPC structure is used to improve the gain. In contrast to the conventional FPC that requires large air gaps between feed and partial reflective surface (PRS), the proposed PRS is integrated with SA on double sides of a single substrate, resulting in a more compact and stable architecture. By using PCB and integrated FPC technology, the gain of this antenna can be 1.2 dB higher than a pure metal SA with the same scale, while the cost is much lower, and the profile increases slightly. For verification, a 220 GHz prototype is designed, fabricated, and measured. The simulated peak aperture efficiency (AE) is 69%, the experiments show a peak gain of 30.1 dBi and a total efficiency (TE) of 38.3%. The 3 dB gain bandwidth is 3.2%. Compared with congener sub-THz planar antennas using low-cost fabrication methods, this antenna can remain a relatively high AE and TE under the high gain (more than 30 dBi) condition, which can be a good candidate for terahertz wireless applications.