Modified Transition for Substrate Integrated Waveguide(SIW) Structures

Abstract

In this paper a new X-band SIW to Microstrip transition based on SIW structure is proposed. The recent transition has better performance in terms of return loss than those of in the traditional Microstrip tapers transition. Chebyshev multi-section matching transformer is utilized in order to inter-stage network between Microstrip and SIW, whereof it is the most optimum and efficient in matching networks theory. The 5th-order Chebyshev polynomial is employed to get about 30 dB return loss. For this purpose, curve-fitting technique is utilized to obtain a mathematical function based on Chebyshev polynomial which presents the optimum position of vias in SIW transition. In order to validation of theoretical method and results, a full-wave simulation is carried out by CST STUDIO SUITE software.