Numerical characterisation of multi-layered CPW directional couplers

Abstract

This paper presents a numerical characterisation of two 3 dB multi-layered CPW directional couplers, which were fabricated at King's College London. The quasi TEM models of the couplers are studied with the help of a 2-dimensional finite element program. The characteristic impedances of even/odd modes for both couplers are obtained and verified. For the purpose of optimisation, the characteristic impedances varying with the coupling gaps in both couplers are also computed.