Multi-carrier frequency modulation broadcast transmitter

A multi-carrier frequency modulation broadcast transmitter comprises an audio interface unit, a digital processing and frequency modulation unit, a radio frequency power amplifier unit, a filter, a coupler and a radio frequency output unit which are in communication connection in sequence. The coupler is in communication connection with the digital processing and frequency modulation unit; the audio interface unit receives external digital and/or analog audio signals and transmits the external digital and/or analog audio signals to the digital processing and frequency modulation unit; the digital processing and frequency modulation unit is used for processing audio signals and outputting the audio signals to the radio frequency power amplifier unit; the radio frequency power amplifier unitoutputs an amplified signal to the coupler; the coupler is coupled with a small signal and outputs the small signal to the digital processing and frequency modulation unit; and the digital processingand frequency modulation