An analysis of small-signal gate-drain resistance effect on RF power MOSFETs
Journal
IEEE Transactions on Electron Devices
Journal Volume
50
Journal Issue
2
Pages
525-528
Date Issued
2003
Author(s)
Abstract
The anomalous dip in scattering parameter S/sub 11/ of RF power MOSFETs with drain-to-spacer offset is explained quantitatively for the first time. Our results show that, for RF power MOSFETs, the input impedance can be represented by a simple series RC circuit at low frequencies and a "shifted" parallel RC circuit at high frequencies. The appearance of the anomalous dip of S/sub 11/ in a Smith chart is caused by this inherent ambivalent characteristic of the input impedance. It is found that an increase of drain-to-spacer offset enhances the anomalous dip. In addition, the anomalous dip in S/sub 11/ of RF power n-MOSFETs can also be interpreted in terms of poles and zeros.
SDGs
Type
journal article