FEM Analysis of a New Type of Cylindrical Stripline Couplers for High-Power Applications

This paper presents design of a new type of extremely low-cost transverse electromagnetic (TEM) cylindrical stripline coupler (CSC) with high-performance suitable for high-power and high frequency applications. Firstly, the effect of the geometrical parameters on the electromagnetic parameters (EM) is studied using finite element method (FEM) in two dimensions (2D). The founded design-curves include all the practically used substrate materials for those TEM-CSC couplers with a wide range of geometrical dimensions (cut depth (u)) and (strip half angle $(\theta)$) varying respectively between 0.1-0.9 and 5-179°. Later, Design results for various CSC-couplers of 50 $\Omega$ and 75 $\Omega$, with 15-dB, 20-dB and 30-dB, operating respectively at 5, 7 and 6 GHz have been presented. The couplers designed are of high directivity and of good isolation which confirm the validity and the usefulness of the realized programs. Finally, we have made a comparison between simulation results in terms of directivity and isolation performances.