Quasi-Static Analysis of a New Wide Band Directional Coupler Using CPW Multilayer Technology

In this paper, a quasi-static analysis of a new wideband directional coupler employing CPW multilayer slot-coupled technique is analyzed and implemented. This coupler uses two CPW lines coupled through a hexagonal slot etched on a common ground plane located between these lines. Firstly, a conformal mapping technique is used to obtain analytic closed-form expressions for the coupler even- and odd-mode characteristic impedances. Secondly, to validate the proposed approach, a prototype of directional coupler was designed, fabricated and tested. Simulation and experimental results show a good performance, especially in term of bandwidth which is 6 GHz (~100 %)