In this paper, we present the optimization works of two disk-type piezoelectric transformers (PTs), the single-output PT and the dual-output PT, by using the elite Genetic Algorithm (GA) and the finite-element solver, NTUPZE. The goal of optimization is to maximize the efficiency under the constraint that the voltage gain is greater than 50 for igniting CCFL. The design parameters are the radii of the outputelectrode sections and the electrode areas, as well as the dimensions of the device structure. With different electrical loading impedances, the voltage gain and the efficiency were computed using the NTUPZE. The results were also validated with measured data. The optimization process is parallelized by the MPI library and a PC cluster for improving the computation efficiency. The characteristics of the optimal designs with different loads are also calculated. The optimized voltage gain and the efficiency for the PT with single output electrode are about 53 and 91.9%, respectively. Also, the voltage gains and the efficiency of PT with dual output electrodes are above 57 and 91%, respectively.
