The present disclosure relates to a polar phased-array transmitter and a mobile terminal. One example mobile terminal includes a baseband chip, the polar phased-array transmitter, and an antenna array. The baseband chip is configured to generate a quadrature digital baseband signal. The polar phased-array transmitter is configured to perform quadrature-to-polar conversion on the quadrature digital baseband signal to generate n amplitude signals and n phase signals, separately perform phase modulation and phase shifting on the n phase signals by using a local oscillator signal to obtain n phase modulation signals, and perform amplitude modulation and power amplification on the n phase modulation signals by using the amplitude signals to obtain n radio frequency signals. n is a natural number greater than 1. The antenna array is configured to obtain the n radio frequency signals from the polar phased-array transmitter, and transmit the n radio frequency signals.