Abstract: A push-pull forward resonant converter based on fixed frequency pulse width modulation (PWM) is proposed for low voltage input DC/DC conversion applications. The push-pull forward structure is adopted on the primary side, and two active switches are introduced on the secondary side based on the combination of a resonant network and a voltage-doubling rectifier. By adjusting the duty cycle of the secondary active switches at a fixed frequency, the converter has two modes of double voltage rectification and quadruple voltage rectification in one switching cycle, thereby achieving wide voltage gain range adjustment. With the introduction of a resonant network, zero voltage switching (ZVS) can be realized for both primary and secondary active switches. Based on the working principle analysis, the relationship between the gain of the converter and the overlapping conduction angle is deduced by using the time-domain analysis method, and the implementation condition of the soft switching of the active switches is analyzed. A 1kW experimental prototype is built, and the experimental results prove the principle analysis's correctness and the topology scheme's feasibility.