CLASS D AMPLIFIER AND WIRELESS COMMUNICATION DEVICE

摘要

A class D amplifier, for limiting the degradation of the EVM of a wireless signal subjected to class D amplification, and a wireless communication device are provided. A bandpass ?S modulator (104) applies bandpass ?S modulation to a signal output from an up-converter (102). A drive amplifier (105) amplifies a signal output from the bandpass ?S modulator (104) up to a signal level operable for a class D amplification unit (107). A switching voltage controller (106) sets the switching voltage threshold of the class D amplification unit (107) to the optimum level on the basis of the effective power value (RMS) of the output signal of the drive amplifier (105). The class D amplification unit (107) uses the switching voltage threshold set by the switching voltage controller (106) to switch and amplify the output signal of the drive amplifier (105).