In the last few years, the fin field effect transistor is emerging as leading structure to continue the scaling of CMOS technology into nanometer regime. Here, we report on the determination of accurate equivalent circuit models from scattering parameter measurements of this novel kind of transistor, since it is an essential step to make a straightforward and physical consistent investigation of the RF behaviour. We focused on the bias dependence and the scalability of the extracted small signal model parameters. It is found that the extracted equivalent circuit parameters of the interdigitated multiple fin transistors under test follow successfully the conventional straightforward scaling rules and their bias dependence is in line with the expectations. (c) 2006 Elsevier Ltd. All rights reserved.