TRANSMITTER

摘要

A transmitter capable of supplying a power supply voltage based on an envelope signal of a transmission signal to the power supply terminal of a power amplifier and amplifying even a wide dynamic range signal with high efficiency and low distortion by means of the power amplifier. The transmitter has a level separator for separating the envelope signal into a signal in a first envelope signal section not more than a reference level and a signal in a second envelope signal section not less than the reference level according to the signal level of the envelope signal, a pulse width modulator for performing the pulse width modulation of the envelope signal in the first envelope signal section, an amplifier for linearly amplifying the envelope signal in the second envelope signal section, a transistor for performing a switching operation according to a pulse width modulation signal to amplify the pulse width modulation signal, and a smoothing circuit for smoothing the combined signal of an output signal of the amplifier and an output signal of the transistor or an output signal of the transistor before the combination, which is supplied to the power supply terminal of the power amplifier.