Abstract:
For the conception and the simulation of the microwave integrated circuits, it’s
important to make up a sample theoretical model that takes into account all the effects
which happen at the main constituting element of these circuits, which is the MESFET
GaAs.
This memory treats the simulation of the MESFET GaAs.that taken place in the
first part, an analytical study of the static characteristics of the component based on the
approximation of the gradual depletion area devoid of free charges .with a
homogeneously doped channel, by holding account the influence of geometrical
dimensions, thus the effect of mobility and the parasitic elements. the effect of the
temperature in the behavior of the transistor MESFET GaAs. Then the influence of the
temperature on the behavior of MESFET GaAs. Taking into consideration the difference
between the temperature of the component and the ambient temperature by electrical
analogy, the thermal resistance RTH is determined as the ratio of the temperature
deviation to the heat dissipation. Note that the heating is generated a distance smaller than
the gate length of the drain side and there is almost no power dissipation under the source
and drain contacts.
The results obtained make it possible to determine the properties of the current
under the effect of the optimal geometrical and physical parameters of the component
with a view to a microwave power amplification application.A compromise is given
between the various parameters as well as the choice of a law of mobility valid for
gallium arsenide. These results allow the development of geometries of the component
adapted of the specific uses, and will play a key role in the field of the CAO of
microwave circuits.
