A polar phased-array transmitter, comprising: a polar signal generator, configured to: generate n amplitude signals and n phase signals, wherein n is a natural number greater than 1; and a transmit array, wherein the transmit array comprises n transmit channels, each transmit channel corresponds to one amplitude signal in the n amplitude signals and one phase signal in the n phase signals, the n transmit channels are configured to: respectively receive the n phase signals, and respectively perform phase modulation and phase shifting on the n phase signals by using a local oscillator signal under control of n phase-shift control signals to obtain n phase modulation signals, and the n transmit channels are further configured to respectively perform amplitude modulation and power amplification on the n phase modulation signals by using the n amplitude signals to obtain n radio frequency signals, wherein the transmit array is coupled to an antenna array, and the n radio frequency signals are transmitted through n antennas of the antenna array; wherein each transmit channel in the n transmit channels comprises: a modulation phase shifter (4021, 500) and a power amplifier; the modulation phase shifter is configured to: receive a corresponding phase signal from the n phase signals generated by the polar signal generator, and perform phase modulation and phase shifting on the corresponding phase signal by using the local oscillator signal under control of a phase-shift control signal corresponding to each transmit channel to obtain a first phase modulation signal; and the power amplifier is configured to: receive a corresponding amplitude signal from the n amplitude signals generated by the polar signal generator, and perform amplitude modulation and power amplification on the first phase modulation signal according to the received first amplitude signal to obtain a first radio frequency signal. wherein each transmit channel further comprises an amplitude decoder, and the power amplifier specifically comprises: multiple digital power amplifiers and a signal power combiner; the amplitude decoder is configured to: decode the first amplitude signal to obtain multiple decoded amplitude signals, and control switch statuses of the multiple digital power amplifiers respectively by using the multiple decoded amplitude signals; and the signal power combiner is configured to combine signals obtained after amplitude modulation and power amplification performed by the multiple digital newer amplifiers into the first radio frequency signal, and to output the first radio frequency signal. a polar signal generator, configured to: generate n amplitude signals and n phase signals, wherein n is a natural number greater than 1; and a transmit array, wherein the transmit array comprises n transmit channels, each transmit channel corresponds to one amplitude signal in the n amplitude signals and one phase signal in the n phase signals, the n transmit channels are configured to: respectively receive the n phase signals, and respectively perform phase modulation and phase shifting on the n phase signals by using a local oscillator signal under control of n phase-shift control signals to obtain n phase modulation signals, and the n transmit channels are further configured to respectively perform amplitude modulation and power amplification on the n phase modulation signals by using the n amplitude signals to obtain n radio frequency signals, wherein the transmit array is coupled to an antenna array, and the n radio frequency signals are transmitted through n antennas of the antenna array; wherein each transmit channel in the n transmit channels comprises: a modulation phase shifter (4021, 500) and a power amplifier; the modulation phase shifter is configured to: receive a corresponding phase signal from the n phase signals generated by the polar signal generator, and perform phase modulation and phase shifting on the corresponding phase signal by using the local oscillator signal under control of a phase-shift control signal corresponding to each transmit channel to obtain a first phase modulation signal; and the power amplifier is configured to: receive a corresponding amplitude signal from the n amplitude signals generated by the polar signal generator, and perform amplitude modulation and power amplification on the first phase modulation signal according to the received first amplitude signal to obtain a first radio frequency signal. wherein each transmit channel further comprises an amplitude decoder, and the power amplifier specifically comprises: multiple digital power amplifiers and a signal power combiner; the amplitude decoder is configured to: decode the first amplitude signal to obtain multiple decoded amplitude signals, and control switch statuses of the multiple digital power amplifiers respectively by using the multiple decoded amplitude signals; and the signal power combiner is configured to combine signals obtained after amplitude modulation and power amplification performed by the multiple digital newer amplifiers into the first radio frequency signal, and to output the first radio frequency signal.