Qucs Frequency Domain Non-Linear Compact Modelling and Simulation of IC Spiral Inductors On Silicon

Abstract

SPICE AC circuit simulation is fundamentally a small signal network analysis of linear or non-linear circuits operating at specified DC bias conditions, where the circuit component values are assumed not to be functions of AC input signal frequency. In the case of RF circuit simulation this assumption can give rise to significant modelling errors. With the recent improvements in General Public License (GPL) circuit simulators this situation is changing, particularly through the introduction of Frequency Dependent Equation-Defined Device (FEDD) models, non-linear current/voltage static and dynamic Equation-Defined Device (EDD) models and user controlled swept signal frequency simulation employing Harmonic Balance steady state analysis. The main purpose of this paper is to introduce a number of novel modelling and circuit simulation techniques that allow, and enhance, the construction of compact device models with embedded behavioural components whose non-linear properties are functions of AC input signal frequency. To demonstrate these new modelling techniques a compact model for a 10 GHz band width spiral inductor integrated on silicon is introduced, its compact model presented, and finally its simulation performance compared with published measured device data.