Analytical Modeling of Multilayered Coplanar Waveguides Including Ferromagnetic Thin Films on Semiconductor Substrates

A review of analytical modeling for conventional coplanar waveguides (CPWs) is carried out. Thus, a refined model based on an electrical equivalent circuit with distributed elements is proposed to properly describe the frequency behavior of a multilayered CPW on a semiconductor substrate. Furthermore, inductors based on such CPWs using a ferromagnetic thin film are studied. Realizations are shown based on CMOS technology and RF measurements are presented. The analytical results are in agreement with the experimental data. Discussions include specific losses originating from the use of a high-resistivity silicon substrate and from the gyromagnetic resonance due to ferromagnetic thin films. These two contributions are accurately evaluated.