Experimental Studies of a Multi-level GaN FET PWM Modulator

The theoretical values of energy losses in a PWM modulator based on GaN FET are being clarified in comparison with the results of previous works by the authors. The dependence of the GaN FET output capacitance on the supply voltage is approximated by a third-degree polynomial. The measurement setup and measurement results for the LMG5200EVM-02 evaluation board are described. The obtained efficiency results at 1 MHz frequency at supply voltages of 15 V, 30 V and 50 V, from 10% to 90% of the duty cycle, showed good matching with the theoretical calculations results throughout the amplitude response. The experimental confirmation obtained allows the use of theoretical expressions to optimize quantization levels in further work.