الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Tlie high electron mobility transistor is a superior device for building a low noise amplifier a! a high frequency. HRMT is now widely used as an extremely low noise device in terrestrial and space telecommunications systems, radio telescopes in the area of astronomy, direct broadcasting satellite television (DBS) receivers and car navigation receivers. This thesis Provides a description of the fundamental ideas of the AlGaAs/GaAs HRMT operation, including basic device theory, material structure and processing techniques. Also present an analytical model for HHMTs, which is based on a single analytical function that describes the electron concentrations in the two dimensional electron gas (2DEG) and in the AIGaAs layer. Besides accounting for the AIGaAs conduction, the mode! includes the effect of mobility degradation, channel length modulation in the saturation region and the series resistances Rs and RD The model results in closed form expressions for the current, transconductance, output conductance and gate capacitance. The pseudomorphic AlGaAs/lnGaAs/GaAs HEMT (PHEMT), has been extensively studied and explained as well as analytical model based on numerical data for PHEMT has been obtained. A single analytical function has been developed with new coefficients suitable to describe the electron concentration in the 2DEG, AIGaAs and neutralized donor layers in pseudomorphic HEMT (PHEMT). The results are compared with the numerical data for sheet concentration, transconductance and gate capacitance and are shown to be in good agreement over a wide range of bias conditions. The results have shown that the PHEMT outperforms conventional HEMT in terms of the sheet carrier concentration, transconductance and gate capacitance Generally speaking, the thesis lies in six chapters, which arc summarized in the introduction.