Simple Analysis and Design of a New Leaky-Wave Directional Coupler in Hybrid Dielectric-Waveguide Printed-Circuit Technology

Abstract—This paper presents a new theory to analyze and de-sign a novel leaky-wave coupler based on a hybrid dielectric-wave-guide printed-circuit technology. The analysis theory is based on a combined method of moments (MoM) geometrical optics (GO) technique, which makes use of the leaky mode complex propa-gation constant. This MoM–GO approach allows to easily obtain the response of the coupler, and to illustratively understand the working mechanism of the proposed structure. A coupler is de-signed to work at 5.5 GHz. Leaky mode results are compared with three-dimensional finite-element method simulations, showing the validity and accuracy of the new theory developed. This novel di-rectional coupler presents interesting advantages when compared to previous wave couplers. Index Terms—Directional coupler, geometrical optics (GO), leaky waves, method of moments (MoM). I