A radio signal receiver includes an input for receiving an input signal having an input carrier frequency modulated by a payload signal to be detected. A frequency converter changes the carrier frequency of the input signal and produce an intermediate signal that is an image of the input signal, and has a carrier frequency equal to an intermediate frequency. A filter circuit filters the intermediate signal. A demodulator eliminates a component, with a frequency equal to the intermediate frequency, from the filtered intermediate frequency, and produces the payload signal. The receiver also includes a detection circuit to produce a level signal representative of a level of the payload signal. a control circuit to apply a control signal representative of the level signal to a control input of the frequency converter, the filter circuit and the demodulator.