USE of COC substrates for millimeter‐wave devices

This article discusses the use of cyclic olefin copolymer (COC) substrates for development of millimeter wave devices. The improvement of performance thanks to the low losses of these substrates is demonstrated using a millimeter‐wave subharmonic mixer working at 220 GHz as test bench. Furthermore, it is the first time this substrate material is used for designing millimeter‐wave components. Some of its main advantages versus conventional substrates are the low losses at high frequencies, the direct gold sputtering, and the robustness. The measured results show 300 K noise temperature and 0.5 dB conversion loss reduction with respect to those obtained by a similar subharmonic mixer developed on a Rogers substrate.