A Ka-Band Bandpass filter with Cylindrical Cavity Resonators using a Substrate Integrated Waveguide (SIW)

A Ka-band Substrate Integrated Waveguide (SIW) 2- poles bandpass filter with metalized cylindrical cavities is proposed for satellite communications and closed range RADARS. The proposed filter inherits the bandpass characteristics of conventional waveguide and bandstop features of periodic structures. Hence, a Substrate Integrated Waveguide filter is designed with linear array of metallized cylindrical cavities implanted inside the same substrate along the side walls and inside the substrate in periodic pattern . A bandpass filter with passband of 38.7–40.5 GHz is designed on a single-layer Rogers RT/Duroid 5880 substrate. Simulated results exhibit insertion loss better than 29 dB and return loss less than 0.1 dB.