Design and Analysis of a Compact Substrate Integrated Waveguide Bandpass Filter for Ku Band Applications

Abstract

The Substrate Integrated Waveguide (SIW) filter is widely used in various RF communications to receive only the desired frequency with least delay. However, the design of SIW filters having high efficiency, compact size and low cost is still a design challenge. In this research work, a compact SIW bandpass filter with tapered via transition and multiple ‘U’ shaped slots is proposed for the Ku band applications. The proposed filter uses a tapered via transition to provide a smooth transition from microstrip line (planar structure) to SIW (waveguide structure) with minimal reflection which results in better S11 performance and wider bandwidth. The stopband performance of the proposed filter is improved significantly by introducing four numbers of ‘U’ shaped slots in the SIW structure which introduces transmission zeros in the upper stopband. The simulated results obtained from HFSS v.14 shows that the proposed filter has improved performance parameters such as low reflection, high isolation, minimal group delay, etc which make it suitable for Ku band applications.