RF SOI Switch FET Design and Modeling Tradeoffs for GSM Applications

A single-pole double-throw novel switch device in0.18¹m SOI complementary metal-oxide semiconductor(CMOS) process is developed for 0.9 Ghz wireless GSMsystems. The layout of the device is optimized keeping inmind the parameters of interest for the RF switch. A subcircuitmodel, with the standard surface potential (PSP) modelas the intrinsic FET model along with the parasitic elementsis built to predict the Ron and Coff of the switch. Themeasured data agrees well with the model. The eight FETstacked switch achieved an Ron of 2.5 ohms and an Coff of180 fF.