Title :
An analysis of small-signal gate-drain resistance effect on RF power MOSFETs
Author :
Lin, Yo-Sheng ; Lu, Shey-Shi
Author_Institution :
Dept. of Electr. Eng., Nat. Chi-Nan Univ., Taiwan, Taiwan
Abstract :
The anomalous dip in scattering parameter S11 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 S11 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 S11 of RF power n-MOSFETs can also be interpreted in terms of poles and zeros.
Keywords :
S-parameters; equivalent circuits; poles and zeros; power MOSFET; RF power MOSFET; Smith chart; anomalous dip; drain-to-spacer offset; input impedance; parallel RC circuit; poles and zeros; scattering parameter; series RC circuit; small-signal gate-drain resistance; CMOS technology; Capacitance; Circuit analysis; FETs; Impedance; MESFETs; MOSFET circuits; Poles and zeros; Radio frequency; Scattering parameters;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2002.808516
