Modified Transition For Substrate Integrated Waveguide(SIW) Structures

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 the traditional Microstrip tapers transition. Chebyshev multi-section matching transformer is used 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 that 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

Keywords:

Chebyshev , Curve-fitting , high-Q factor , Permittivity , RWG , SIW , TEM , TE , X-band