Miniaturized W-Band Gap Waveguide Bandpass Filter Using the MEMS Technique for Both Waveguide and Surface Mounted Packaging

A novel miniaturized and light weight W-band bandpass filter (BPF) is proposed based on the gap waveguide (GWG) concept using the micro-electromechanical system (MEMS) technique. The BPF is achieved by cascading four rectangular GWG resonant cavities with designed rectangular and cross-shaped coupling structure. Two standard WR-10 waveguide coupling windows are designed as the input/output couplings, which contributes to the flexible application in various packaging configurations. By utilizing the classical coupling matrix theory, the proposed MEMS GWG BPF is designed to work from 89.8 to 97.4 GHz, which is fabricated by the deep reactive ion etching process using the silicon wafers, and the fabricated silicon wafers are also electroplated and bonded together as a whole structure. The measured insertion loss is within 1.6 dB, and the return losses are larger than 15 dB.