Performance modeling of RF power MOSFET's

This paper presents an analytical study of the RF performance of Si pn,ver MOSFET's. Si MOSFET's are rapidly becoming popular in RF applications. Alth ough circuit simulation models have been presented explaining the static pe rformance of these devices, the correlation of device physical parameters w ith RF performance has not been studied extensively. In this paper, based o n the equivalent circuit representation of a power MOSFET, static and large -signal analysis have been carried out to study the RF performance for VDMO SFET and LDMOSFET devices. It has been shown that transconductance compress ion due to the JFET region leads to degradation of high-power RF performanc e, It is also shown that LDMOSFET has higher power gain than VDMOS, but ste eper degradation with input power. Velocity saturation in the MOS channel a nd presence of the JFET region are shown to strongly influence the RF perfo rmance of the two devices.