W-band Quintuple-mode Filter using Quarter-mode Substrate-Integrated Waveguide Resonators

This paper presents a quintuple-mode filter by modifying a folded quarter-mode substrate-integrated waveguide cavity. A W-band bandpass filter is designed and fabricated to verify the idea. The multi-layer structure using photosensitive polymer Benzocyclobutene as dielectrics was illustrated. Four transmission zeros were designed to improve the out-of-band performance and insertion loss is 1.97 dB at 89 GHz with a fractional bandwidth of 22.5%. The packaged filter exhibits close agreements between the simulation and measurement results and has the advantages of compact configuration and easy integration with other devices.