DOHERTY POWER AMPLIFIER AND SIGNAL PROCESSING METHOD

摘要

A Doherty power amplifier is provided, which comprises: a broadband peak power amplifier whose input receives signals with at least two different narrowband frequencies, and at least two narrowband carrier power amplifiers connected in parallel with the peak power amplifier, whose inputs receive signals with a single narrowband frequency respectively and whose outputs are connected serially with a first impedance transformation network respectively. The output impedance of the combination of signals from the peak power amplifier and carrier power amplifiers is transformed into the load impedance through a second impedance transformation network so that the active load pull is made to the carrier power amplifiers through the peak power amplifier. A signal processing method is also provided. The problem of the narrow working bandwidth of the current Doherty power amplifier can be solved while the Doherty power amplifier is enabled to work in two or more subfrequencies simultaneously.