(An) RF Model of the MOS varactor fabricated in CMOS technology

Abstract

A novel RF model of an accumulation-mode MOS varactor has been proposed. This model, which is composed of the physically meaningful parameters, can describe the characteristics of device with the simple equations valid in both accumulation and depletion regions. For easy integration into commonly available circuit simulators, a single topology with the lumped elements derived from the device structure has been suggested. With directly extracted parameters based on the Z-parameter analysis on the equivalent circuit, excellent agreements between measured data and simulation results were obtained without any optimization steps after the parameter extraction in the frequency range up to 18 GHz and the overall bias range.