부산대학교 도서관

Terahertz sources require compact lenses for efficient outcoupling and manipulation of terahertz waves. Traditional terahertz lenses are bulky and require high-precision fabrication techniques, such as micromachining, which limit their flexibility in integrated systems. As an alternative, we present a planar high-gain cavity antenna integrated with a waveguide feed. The antenna is made by laser-etching of high-resistivity float-zone silicon to create nonuniform hole arrays, which function as gradient-index lenses for beamforming. To address the insufficient phase coverage range caused by limitations in feasible etching depth and the intrinsically tapered side walls of the holes, direct laser-etching is performed on both sides of the silicon wafer. A cyclic olefin copolymer sheet is placed on top of the silicon wafer to aid silicon–air impedance matching. The silicon cavity antenna is experimentally validated, with results confirming that a maximum broadside gain of 19 dBi can be achieved at the center frequency of 275 GHz, with a 3 dB bandwidth of around 29%. We further demonstrate that such a high-gain antenna is applicable to error-free point-to-point short-range wireless signal transmission. A demonstration of uncompressed 4K-resolution video transmission is also included. The proposed planar antenna design has the advantages of a significantly reduced device profile and is a cost-effective solution for future practical array-level designs.