Unilateral Fin Line Coupler with PBG Substrate

The photonic band gap (PBG) crystals have been used as a perfectly reflecting substrate for many millimeter wave applications, in this work the fin line directional coupler with substrate PBG was analyzed using the TTL - transverse transmission line - method. Compared to older full wave methods the TTL is an efficient tool to determine the coupler characteristics, making possible a significant algebraic simplification of the equations involved in the process. In order to analyze the structure the effective dielectric constant, the attenuation constant and the coupling were determined. The results obtained for this application and the conclusions are presented.