Modelling and analysis of Substrate Integrated Waveguide (SIW) and half-mode SIW (HMSIW) band-pass filter using reactive longitudinal periodic structures

Design of planar Substrate Integrated Waveguide (SIW) and Half Mode Substrate Integrated Waveguide (HMSIW) Band Pass Filter (BPF) loaded with periodic array of longitudinal slots are proposed in this paper. The proposed method introduces simple periodic reactive slots which have the property to create resonance to obtain stopbands at multiple frequencies. Transmission zeroes as well as Insertion Loss of the BPFs designed by using these technique are relatively easy to control. The property of these periodic slots is further analyzed to reach a concrete conclusion which provides the design engineers luxury to choose stopbands as per individual applications. Major spectrum of Microwave X-band and Ku-bands are covered with minimal Insertion Loss. Nearly 50% reduction in size is also obtained by using HMSIW structures. The designs are fabricated and the concept is successfully validated with measured results over a material of dielectric constant 3.2 and thickness of 30 mils. Methods proposed in this paper are extremely simple to design and suitable for Industrial or Scientific productions.