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An improved analytical two dimensional (2-D) model for AlGaN/GaN modulation doped field effect transistor (MODFET) has been developed. The model is based on the solution of 2-D Poisson's equation.The model includes the spontaneous and piezoelectric polarization effects. The effects of field dependent mobility, velocity saturation and parasitic resistances are included in the current voltage characteristics of the developed two dimensional electron gas (2-DEG) model. The small-signal microwave parameters have been evaluated to determine the output characteristics, device transconductance and cut-off frequency for 50 nm gate length. The peak transconductance of 165mS/mm and a cut-off frequency of 120 GHz have been obtained. The results so obtained are in close agreement with experimental data, thereby proving the validity of the model.

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In order to manage the flow of power in the dual bridge type converter, a modulation technique called phase shifted square wave is employed. As an outcome, increased range of ripples in current is resulted, and that further provokes the vibration in inductance and capacitance circuit. Due to this effect, there exists uncertainty in the value of current and voltage, failure of operating components and stress in the filter. To miti-gate the above ill effects, three level modulation can be done using three phase shift square wave control angles. These three angles now elimi-nate the harmonics in chosen DC link and the harmonic eliminating procedure is justified and simulated.