Analysis and Design of a Transient-State Resonant Converter Used as a Frequency Multiplier

The main contribution of this paper is to show the analysis and design of a resonant converter which was designed to operate in the transient stage and with underdamped response, where the resonant network stage has a frequency equal to “n” times the frequency of the switching stage (fsw) “fo = nfsw”. The main advantage of this design methodology is to be able to operate the converter with frequencies higher than 1 MHz in the resonant network stage, without obtaining high levels of losses in the inverse stage. To validate this design methodology, a full bridge resonant converter acting as a frequency multiplier was implemented for a low power wireless power transmission application. For the experimental tests, a base frequency of 300 kHz was decided in the inverting stage, with a frequency multiplication of n = 3, 5, 7 in the resonant network stage (900 kHz, 1.5 MHz, 2.1 MHz) for an output power of 12 watts. Experimental tests proved the operation of the converter acting as a multiplier, where it was possible to reduce losses in the inverter stage, achieving efficiencies of up to 93% in the switching stage with frequencies higher than 1 MHz.