Monolithic Millimeter-Wave Air-Filled Waveguide Resonator for Filter Applications

This letter demonstrates the first successful realization of a monolithic wafer-level integrated air-filled waveguide resonator in the millimeter-wave W-band. The fabrication of the proposed design builds upon previously published processes by spin-coating two layers of thick positive resist to construct the waveguide channel. The fabricated design achieves an insertion loss of 2.12 dB, unloaded quality factor of 97.6, and 3-dB fractional bandwidth of 3.0% at the center frequency of 76.6 GHz. The proposed concept illustrates a new technique for integrated filter realization at such frequencies.