摘要

The feasibility of a new full bridge high intensity focused ultrasound (HIFU) amplifier system with harmonic cancellation is evaluated in this study. Harmonic cancellation technique is applied to these power amplifiers, which can eliminate the 3rd harmonic and all even harmonics. Since this technique requires two channels of phase signal to control one channel of power amplifier, the signal generator is required to double its output. The transducer array proposed in this study has 100 elements. So we choose an FPGA chip to generate 200 driving signals, and each channel has a phase resolution of 2 ns, less than 1°. The phase signal from the FPGA meets the requirement of driving the power amplifiers. The output waveform of one channel of power amplifier (voltage across the transducer) is evaluated, and shows fewer harmonic components.