A Frequency Multiplication Resonant Inverter With Constant Frequency Phase Control

The schematic and analysis of a voltage-fed resonant inverter are presented in this paper. The topology of the inverter allows operation of the resonant tank at higher harmonics and multiples of the switching frequency. The resulting loss in voltage gain is compensated through the use of multiple commutation poles employing low-cost modestly rated MOSFETs. The proposed topology can control power throughput at a fixed frequency through pole phase-shift modulation. Zero voltage switching is maintained down to no load and within the entire input voltage range. Measurements from a multimegahertz 100-W inverter confirm the theoretical predictions, as well as the suggested design and control approach.