SOI CMOS Transistors for RF and Microwave Applications

The new communication markets are vey demanding: high frequency, high degree of integration, low power consumption. Silicon-on-Insulator offers many advantages and this paper illustrates the potentialities of this technology for RF and microwave applications. After an overview of the SOI material, the properties of the SOI MOSFET's are analyzed and compared to bulk Si MOSFET's. The models of transmission lines and inductors on SOI are compared and further used in the on-wafer characterization of the transistors. Various models for the transistors are presented and their limitations are given. A new model is described, valid from DC to the microwave region. This model agrees very well with the measurements for various transistor dimensions. Finally, various RF and microwave circuits are presented. This paper does not fully describe all the properties and applications of SOI but the numerous references offered to the reader help him to gather more informations