PCB analysis method by S-parameters for power inverters with GaN devices in parallel

A method and a modeling procedure to simulate and optimize a half bridge power inverter with GaN (gallium nitride) transistors in parallel is proposed. The method is based on S-parameters calculation of the PCB (Printed Circuit Board) and the definition of relevant frequency simulation allowing to characterize harmful couplings effects of the PCB on transistors. The definition of the frequency analysis is explained on the criterion of the current sharing between transistors in parallel, considering the functional switching sequence of the inverter. The frequency analysis is carried out on a four-port Y matrix of the switching loop including PCB couplings and relevant components. The efficiency of the method is demonstrated by the successful modification of the PCB.