A Five-Parameter Model of the AlGaN/GaN HFET

Abstract

We introduce an analytic expression for the drain current I d (V gs , V ds ) of an AlGaN/GaN heterojunction field-effect transistor (HFET) as a function of its gate and drain voltages. We derive the function from a compact physical model of conduction current in the HFET. The proposed expression for the current is configured by five parameters, which can be expressed in terms of the geometry and materials of a device. We extend the model to small-signal RF operation by embedding it in a 12-parameter RLC network that represents terminal feed impedances and device parasitics. We adjust the parameters of the extended model to simultaneously fit dc and RF measurements of an industrial transistor.

Evaluation of Pulsed I–V Analysis as Validation Tool of Nonlinear RF Models of GaN-Based HFETs

“…The result is a nominally sinusoidal RF drain voltage, v ds (t), waveform and a half-wave rectified RF drain current, i d (t), waveform that flows primarily when the voltage is at a minimum resulting in improved efficiency. These RF-I -V waveforms were measured over a range of fundamental load impedances and at five different dc drain bias points (10,15,20,25, and 28 V) for five different devices on each wafer.…”

TCAD Simulations and Small Signal Modeling of DMG AlGaN/GaN HFET

“…Since analytical models help us to understand internal solid state device physics thus expected to be consistent with physical behavior of device. An accurate small signal model of HFET is extremely valuable for designing of important active circuits generally used for high frequency applications [8][9] These small signal compact models define physical characteristics and various limitations of active devices accurately [11], thus used for design of low noise power amplifiers by electronics and microwave engineers in industry. Small signal models of advanced devices are needed for CAD based simulations [12] for analysis and validation of newly developed device structures [13].…”