Back-gate bias effect on FDSOI MOSFET RF Figures of Merits and parasitic elements

This work demonstrates that the back-gate terminal of a 28nm FDSOI MOSFET can be used up to several tens of GHz for signal processing. Furthermore, the dependence of the main RF figures-of-merit on the back gate bias are experimentally extracted using a 3-port characterization in the frequency range of 10 MHz – 26.5 GHz. We propose a small-signal equivalent circuit constructed based on 3-port measurements allowing for more complete extraction of parasitic elements comparing to the 2-ports one. The effect of back-gate bias on cut-off frequencies is demonstrated and explained in terms of its influence on the relevant parasitic elements.