X-Band CPW 90° Hybrid Based on Substrate Integrated Waveguide

Substrate integrated waveguide (SIW) is a famous alternative in order to reach a trade-off solution between waveguide and planar technologies in terms of high quality factor, high gain, volume, flat structure, low cost, easy to fabricate, low radiation losses, power handling, simple integration and allow the inclusion of transmission zeros to improve the edges of the bands. In this letter, a novel Substrate Integrated Waveguide (SIW) coupler is investigated based on the Co-Planar Waveguide (CPW) structure. The proposed coupler is compact and operates in the X-band near 9 ~ 9.9 GHz frequency. It consists of a two-way SIW transmission line combined with an improved CPW to microstrip transition. The simulations performed by CST Microwave Studio, and wideband responses are acceptable.

Keywords:

Coupler , Co-Planar Waveguide (CPW) , Substrate Integrated Waveguide (SIW)