Accuracy issues in a high-level model for MEMS varactors

We present accuracy issues for an equivalent circuit model and an AHDL model (high-level models) of MEMS varactors. Simulations of different MEMS varactor structures were done using the high-level models and an electrostatic/mechanical solver EMS.9. The limitations of the varactor high-level models are presented in the context of a RF MEMS VCO operating at 1.6 GHz in a TSMC 0.35 m CMOS technology.