A Miniature W-band Substrate-Integrated Waveguide Cavity Bandpass Filter Using GaAs-based IPD Technology

This paper presents a miniaturized substrate-integrated waveguide (SIW) cavity bandpass filter (BPF) using integrated passive device (IPD) technology for W-band applications. With two side-by-side SIW cavities coupling via an aperture, the cavities resonate in the TE
101
mode to determine the center frequency. Also, the transmission zero at a higher frequency is created owing to the excited TE
102
mode. By varying the aperture width, the bandwidth (BW) of the filter could be determined via coupling strength and the TE
102
mode frequency. With a center frequency of 100 GHz, the proposed SIW filter demonstrates a 3-dB BW of 5.1 GHz (97.4-102.5GHz) with a low insertion loss (IL) of only 1.89 dB, and the return loss is better than 20 dB in the passband. This work achieves a low IL and fractional BW (FBW) of 5.1 % with a compact size of 1.48 mm
²
, which is among the best compared to previously reported W-band chip BPFs.