Substrate Integrated Waveguide Filters for Airborne and Satellite System Applications

Substrate integrated waveguide (SIW) technique provides a low-profile, low-cost and low-weight scheme while maintaining high performance, which is particularly useful for airborne and satellite system applications. In this paper, two K-band 4^th-degree and 5^th-degree oversized SIW cavity filters with symmetrical inductive post-wall irises are designed and realized on the basis of a conventional microwave substrate of Rogers RT/Duroid 6002 by arrays of via. A finite transmission zero is assigned by the interaction between the fundamental TE₁₀₁ mode and the higher-order TE₃₀₁ mode to improve the attenuation in the transmit band. A good agreement is observed between the simulation results and measurement result even though there is some difference due to the fabrication error.