POWER SUPPLY MODULATION DEVICE AND AMPLIFICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a high efficiency power supply modulation device.SOLUTION: The power supply modulation device includes an AC amplifier 144 for outputting power corresponding to an input signal Venv, and a switching power supply 143 for outputting power corresponding to a low frequency component of the input signal. An output of the AC amplifier 144 and an output of the switching power supply 143 are added up to output power Vd. The output power Vd is negatively fed back to an input side of the AC amplifier 144. The switching power supply 143 is configured such that the output of the switching power supply 143 substantially includes a ripple voltage, and can cover a wide band. The wide band of the switching power supply 143 improves power supply efficiency. The ripple voltage is canceled by the negative feedback.