A scalable physical model for coplanar waveguide transition in flip-chip applications

In this paper we present a new scalable electrical lumped model for coplanar waveguide (CPW) transitions in flip-chip modules. The model is developed by a proper reduction of the well-known electrical model of two coupled coplanar waveguides. Electromagnetic simulations of the structure are used to extract model parameters for various bump configurations. Regression models are then used in order to scale the values of the lumped elements with physical dimensions of the system. The good agreement between fast circuit simulations and time-consuming finite element analysis, indicate that the model is well suited for modeling flip-chip CPW in the high-GHz range.