Modeling of frequency and temperature effects in GaAs MESFETs

The small-signal conductance and large-signal I-V characteristics of conventional 1- mu m recessed-gate GaAs depletion-mode MESFET devices have been investigated. The small-signal saturation-region output conductance g/sub ds/ of a conventional GaAs MESFET is dependent on both frequency and temperature. These dependencies present serious difficulties in the design of many GaAs integrated circuits, since the small-signal voltage gain in analog circuits and the propagation delay in digital circuits depend on g/sub ds/, and no accurate simulation model is available. A semiempirical model for the frequency-dependent parameters in GaAs depletion-mode MESFETs is presented. An analytical formulation of temperature dependence is also included by an extension of the basic Curtice model. The resulting model is significantly more accurate than other models, which have not previously incorporated frequency- and temperature-dependent effects.<
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