Microfabrication of a Monolithic Air-Filled Half-Mode Waveguide for Millimeter-Wave Applications

Abstract

This letter presents the first successful on-wafer fabrication and characterization of a fully monolithic air-filled half-mode waveguide (HMWG) for millimeter waves. Utilizing a flexible microfabrication process, a thick sacrificial layer is employed to build and then release 3-D structures on-wafer. The measured prototype achieves an attenuation of 0.31 dB/mm at 85 GHz, while miniaturizing the footprint of the conventional waveguide by 56%. The proposed concept highlights the potential of monolithic HMWGs for enhanced integration technology suitable for high-performance millimeter-wave 5G communication systems.