In this paper, we discuss the RF noise properties of SOI MOSFETs, and we present a suitable model for nanoscale fully-depleted SOI MOSFETs, which is derived from a compact quasi-static SOI MOSFET model by properly extending it to the high frequency regime, using the active line approach and taking into account all the extrinsic parameters. We have used a physically-based noise modeling which takes account diffusion related fluctuations; this allows to study fundamental noise parameters close to the current noise sources and to discuss the downscaling of these noise sources. Finally, we have extended our study to Double-Gate devices, using as a basis a quasi-static model recently presented. © 2005 American Institute of Physics.