Miniaturized 3-dB Micromachined Broadband Lange Coupler On Alumina Substrate

Abstract

This work presented the fabrication and measurement of 3-dB broadband miniaturized Lange coupler on Alumina substrate. The measured results are in good agreement with the simulated ones. The fabrication steps are simple. Gold bond wires of 50 micron diameter used to connect the strips and the use of bond wires same time eliminating the need of making air-bridges that are generally used to suppress higher order modes in coplanar waveguide (CPW) and a business of some money addition to the fabrication cost thus making fabrication cheaper. Alumina (εr=9.8) substrate of 5 mil thickness used as it shows low surface loss and to achieve higher frequency it is mandatory to choose a thinner substrate (<15 mil) also to achieve realizable strip width. The fabricated coupler having area of 2mm×1.28mm.