Micromachined coplanar waveguides: design, realization and test up to 40 GHz

The micromachining technique is suitable of interesting applications at microwave and millimeter wave frequencies. The dispersion control as well as the decrease in the level of the propagation losses reveals immense potentialities for the realization of planar waveguides and filters. Moreover, the packaging optimization allows the possibility of integrated devices for both ground and space applications. In this paper, results ore presented on the technological processing for the realization of simple coplanar waveguide (CPW) structures on silicon wafers, together with the design criteria and the experimental validation of the obtained structures. A comparison is performed between CPWs realized on bulk silicon wafers and on SiO₂ /Si₃N₄/SiO₂ membranes to demonstrate the improvement obtained by using the membrane solution