Title :
Analytic solution of the velocity-saturated MOSFET/MODFET wave equation and its application to the prediction of the microwave characteristics of MODFETs
Author :
Roblin, Partick ; Kang, Sung Chan ; Morkoç, Hadis
Author_Institution :
Dept. of Electr. Eng., Ohio State Univ., Columbus, OH, USA
fDate :
7/1/1990 12:00:00 AM
Abstract :
An AC model for the saturated MODFET is reported. The MOSFET/MODFET wave equation accounting for velocity saturation and channel length modulation is derived. An exact solution of the wave equation is obtained in terms of Bessel functions. A frequency power series is used to derive analytic expressions for the intrinsic Y -parameters. This AC model is applied to the prediction of the microwave characteristics of 1-μm AlGaAs/GaAs MODFETs and GaAlAs/InGaAs/GaAs pseudomorphic MODFETs. The parameters used by the AC model are extracted by fitting the I-V characteristics. The parasitics are either estimated or measured. A good prediction of the scattering parameters measured from 2 to 18.4 GHz is achieved for different biases. The deviation of the calculated unilateral power gain from the measured values was on average 1.25 and 2.18 dB for the conventional MODFET and the pseudomorphic MODFET, respectively
Keywords :
high electron mobility transistors; insulated gate field effect transistors; semiconductor device models; solid-state microwave devices; 1 micron; 2 to 18.4 GHz; AC model; AlGaAs-GaAs; Bessel functions; GaAlAs-InGaAs-GaAs; I-V characteristics; channel length modulation; frequency power series; intrinsic Y-parameters; microwave characteristics; parasitics; unilateral power gain; velocity saturation; velocity-saturated MOSFET/MODFET wave equation; Frequency; Gallium arsenide; HEMTs; Indium gallium arsenide; MODFETs; MOSFET circuits; Partial differential equations; Power measurement; Predictive models; Scattering parameters;
Journal_Title :
Electron Devices, IEEE Transactions on
