High-Gain Yagi–Uda Antenna on Cyclic Olefin Copolymer Substrate for 300-GHz Applications

The cyclic olefin copolymer is a dielectric material with very attractive mechanical and electrical properties for millimeter- and submillimeter-based devices as recently demonstrated in a few applications. Here, we present the possibility of employing this material as a substrate for traveling-wave antennas through the design, fabrication, and characterization of a Yagi-Uda antenna working around 300 GHz. The developed fabrication process can be scaled to higher frequencies to take advantage of the extremely low absorption of such a dielectric at terahertz (THz) frequencies. The measurements agree well with the calculations, and a high gain of 15.4 dB has been achieved at 300 GHz. The measured bandwidth for a reflection coefficient of -10 dB is 10 GHz, and the radiation pattern presents a symmetrical main lobe with an angular width below 25 ^°.