CASCODE POWER AMPLIFIER FOR AMPLITUDE MODULATION

摘要

A power amplifier of a cascode structure for amplitude modulation is provided to prevent switching noise and to reduce the area of a chip and power consumption by modulating a carrier signal according to information of a baseband signal without using a mixer or a filter. A radio transmitter includes a frequency generator for generating a carrier signal of predetermined frequency and a power amplifier(31). The power amplifier is operated by receiving power voltage(VDD) of predetermined magnitude and biased on the basis of the voltage level of a baseband signal, receives a carrier signal and generates a radio signal(RF OUT) by amplifying the carrier signal according to the biased state. The power amplifier has a bias unit for generating bias voltage according to the voltage level of the baseband signal.