Large signal substrate modeling in RF SOI technologies

This paper describes a large signal Silicon on Insulator (SOI) substrate modeling methodology for high power circuit applications such as RF Switches. It is shown that the use of a varactor in place of a linear capacitor representing the buried oxide (BOX) improves the harmonic predictions of the circuit. The new substrate model is validated against 2^nd and 3^rd harmonics of an RF SOI switch operating at 890 MHz.