New method class D amplifier which enables reduction of RF noise and signal distortion

Proposed class D amplifier can reduce its output amplitude voltage to half by modulating output pulse polarity according to input signal polarity. And the modulation can reduce harmonics of output pulse to about half with compensating signal delay. Moreover, the proposed amplifier can reduce signal distortion occurred after PWM stage. In measured results, the proposed amplifier was able to decrease fundamental and odd harmonics in output pulse by 41.4dB or more. Moreover, the proposed amplifier was able to decrease the second harmonic distortion by 16.3dB. Therefore, THD of proposed amplifier was reduced to half or less in large output signal.