W-band substrate integrated waveguide filter with cross-coupling

A W-band substrate integrated waveguide bandpass filter with cross-coupling are proposed and designed for RF front-end. The cross-coupling between the non-adjacent resonators is used to generate the finite transmission zero point away from the passband to improve stopband performance. A fourth-order filter with passband of 92-94 GHz is fabricated on a single-layer Rogers RT/Duroid5880 substrate using linear arrays of metallized via-holes by a standard printed circuit board process. Simulated in-band insertion loss is 2.5dB or better, and the stop-band attenuation in the frequency band of 90-95GHz is better than 35dB. Measured in-band insertion loss is better than 7.5dB, and the stop-band attenuation in the frequency band of 91-98GHz is lower than 30dB.