A 1.0-THz High-Gain Metal-Only Transmit-Array Antenna Based on High-Precision UV-LIGA Microfabrication Technology

Implementing high-gain antennas operating in exceedingly high THz regions, e.g., the challenging WR-1.0 band, relies significantly on dependable microfabrication technologies. Due to the advantages of high precision, low cost, and high uniformity, this article presents a 1.0-THz 64 × 64-element high-gain metal-only transmit-array (TA) antenna fabricated using ultraviolet photolithography techniques in conjunction with micro electroforming (collectively, UV-LIGA). As a highly parallel batch fabrication technology, the UV-LIGA consists of three main stages in this case, namely film fabrication, electroforming, and assembly. In full consideration of array structural stability and intrinsic connectivity based on the UV-LIGA, the proposed phasing element design employs a five-layered folded-slot structure with four air-filled spacer layers. By placing a shim layer between two contiguous folded-slot slices, whose thickness can be varied by modifying the electroforming time, each air gap can be accurately and flexibly ensured. The fabricated TA prototype is experimentally validated in a THz chamber. The maximum gain is 36.47 dBi, and its corresponding aperture efficiency is equal to 25.96%. The measured 3-dB gain bandwidth is from 0.79 to 1.03 THz.