A unified model for on-chip CPWs with various types of ground shields

Abstract

Coplanar waveguides (CPW) are promising candidates for high quality passive devices in millimeter-wave frequency bands. In this paper, CPW transmission lines with and without ground shields have been designed and fabricated on 65nm CMOS technology. A physical-based model is proposed to describe the frequency-dependent per-unit-length L, C, R, and G parameters. Started from a standard CPW structure, influences of different kinds of ground shields have been analyzed and included into the general model. The accuracy of the model is confirmed by experimental results.