715 www.ijergs.org A Coupled Microstripline Directional Coupler Simulated Using CST-MWS

Abstract — Directional Coupler (DC) is a passive device which is primarily employed for monitoring purposes. It is also used in wide range of applications such as antenna feeds, balanced mixers, modulators, phase shifters, as power combiners, as reflectometers. The paper discusses the designing issues of a coupled line-microstripline directional coupler and designs a directional coupler yielding directivity of ~21 dB for the frequency 505.8 MHz. The effects of strip thickness, and substrate thickness have been studied while optimizing the design parameters in order to enhance the directivity of the coupler