Signal processing circuit, radio frequency signal transmitter, and communications device

A signal processing circuit, comprising a splitter, a radio frequency signal converter, a first branch power amplifier, a second branch power amplifier, and a combiner, wherein the splitter is directly connected to the radio frequency signal converter, the radio frequency signal converter is directly connected to the first branch power amplifier and the second branch power amplifier, and the first branch power amplifier and the second branch power amplifier are directly connected to the combiner, wherein at least one of the first branch power amplifier or the second branch power amplifier comprises a Doherty power amplifier;

• the splitter is configured to:
• receive a first digital signal, split the first digital signal into at least one first branch digital signal and at least one second branch digital signal based on an input power of the first digital signal, and
• output the at least one first branch digital signal and the at least one second branch digital signal to the radio frequency signal converter, wherein at least one of a ratio of an amplitude of the at least one first branch digital signal to an amplitude of the at least one second branch digital signal, or a phase difference between the at least one first branch digital signal and the at least one second branch digital signal varies with the input power of the first digital signal;
• the radio frequency signal converter is configured to:
• convert the at least one first branch digital signal and the at least one second branch digital signal into at least one first branch radio frequency signal and at least one second branch radio frequency signal, and
• output the at least one first branch radio frequency signal and the at least one second branch radio frequency signal;
• the first branch power amplifier is configured to:
• amplify the received at least one first branch radio frequency signal, and output the amplified at least one first branch radio frequency signal to the combiner;
• the second branch power amplifier is configured to:
• amplify the received at least one second branch radio frequency signal, and
• output the amplified at least one second branch radio frequency signal to the combiner;
• and
• the combiner is configured to:
• receive at least one output signal output by the first branch power amplifier and at least one output signal output by the second branch power amplifier, adjust, based on the at least one output signal output by the second branch power amplifier, the at least one output signal output by the first branch power amplifier, and
• output the adjusted at least one output signal.