Design and Analysis of 150° Bend SIW and Corrugated SIW Bandpass Filter with Multiple Transmission Zeroes Using Reactive Periodic Structures Suitable for Microwave Integrated Circuits (MICs)

Microwave multi-band bandpass filter using substrate integrated waveguide (SIW) and corrugated SIW (CSIW) over Neltec NH9320 with dielectric constant of 3.2, thickness 30 mil and loss tangent tanδ = 0.0024 are presented in this paper. Firstly, 150° bend in the SIW BPF has been provided in SIW multi-band filters in view of its overall size reduction compared to planar un-bend structures and integration ability as required in microwave integrated circuits. Secondly, Reactive periodic slots are introduced over the SIW surface to obtain multiple transmission zeroes within the passband. These slots are bend to 150° in alignment to the 150° bend within the waveguide section. The method presented is further extended for designing CSIW multi-band BPF. Impacts of several parameters of the periodic slots (which are also 150° bend in accordance with the SIW structure) are analyzed. The measured results ensure improved filter performance like low reflection as well as improved isolation. The angular bend used in the BPF enables it to be integrated with other planar circuits within the same PCB material. Passbands obtained within the microwave Ku-bands are suitable for use in Direct Broadcasting Satellite communication systems.