self-consistent lumped radio frequency linear network model for MOSFETs taking into account the gate resistance

This paper describes a self-consistent lumped linear network model for MOSFETs that takes into account the distributed nature of the gate resistance. The model is verified with experimental results. The self-consistent model consists of placing a lumped resistance in series with the gate. The lumped resistance takes the value of the total gate resistance divided by a factor of three. To second order in j omega, this is shown to be almost an exact approximation in determining all y-parameters and the equivalent noise resistance. The third-order terms, however, give rise to a 17% error. The value of ft for a MOS transistor shows no dependence with the gate resistance to all orders in j omega. Furthermore, we also show that the thermal noise arising from the distributed gate resistance does not contribute to any additional equivalent input current noise.