Design of the Class-Φ₂ Inverter Considering the Duty Cycle of the Drain-Source Voltage Waveform

This paper proposes a design method for the class-Φ2 inverter that incorporates the duty cycle of the drain-source voltage waveform. In conventional designs, zero-voltage switching (ZVS) is achieved by tuning circuit parameters based on the magnitude and phase of the drain-source impedance. However, such empirical adjustments often fail to satisfy the target output power under varying design conditions, necessitating iterative trial-and-error optimization. To overcome this limitation, the proposed method introduces ZVS conditions that account for the duty cycle of the drain-source voltage waveform and integrates it into the resonant filter design. Both analytical and experimental results confirm that the proposed approach successfully achieves the desired output power using calculated component values, while effectively minimizing the need for iterative tuning.