High-Gain Luneburg Lens on COC Substrate for 300-GHz Applications

A Luneburg lens quasi-optical beam-former is used to excite a leaky-wave antenna at 275 GHz. Both the lens and the antenna are fabricated on a Cyclic Olefin Copolymer (COC) substrate. The full system is etched on the polymer by photolithography. Numerical results show a reflection coefficient lower than −24 dB and a gain higher than 21 dBi over a 40% fractional bandwidth, spanning from 220 GHz to 330 GHz. The efficiency of the antenna is estimated to be 28% at the center frequency (275 GHz).