A state of the art Monte-Carlo simulator is applied to the investigation of the RF performance of bulk MOSFETs designed according to the prescriptions of the 2005 ITRS Roadmap for analog and mixed signal applications, and of a 53 nm ultra-thin-body (UTB) single-gate (SG) SOI MOSFET. We provide an analysis of the signal-delay build-up along the channel and an investigation of the scaling properties of the parameters of the AC equivalent circuit, the transition frequency FT, and the 3dB bandwidth of the voltage gain in common-source configuration. The effects of ballistic transport and their impact on the AC figures of merit are investigated for short UTB double-gate MOSFETs
