A new highly-scalable equivalent circuit model for on-chip symmetrical transformer with accurate substrate modeling

Abstract

A new equivalent circuit model for on-chip symmetrical transformers is presented with all the model elements driven from fabrication specifications. Two extra coupled transformer loops are developed for each coil to calculate the parameters of skin effect, proximity effect and reflective effect of substrate eddy current respectively. Model accuracy is demonstrated by comparing simulated and measured S-parameters, coils inductance, coupling coefficient, and maximum available gain over a wide range of geometry configuration.