A signal receiver comprising: an antenna interface for receiving signals from an antenna; analog signal processing circuitry (208a-208c) coupled to the antenna interface for processing the received signals to produce filtered signals; sampling circuitry (210a-210c) to sample the filtered signals so as to produce digitized received signals; a digital compensator (212a-212c) to receive the digitized received signals and compensate for non-uniform group delay introduced by the analog signal processing circuitry (210a-210c) to produce compensated digitized received signals; and a digital processor to process the compensated digitized received signals so as to produce a result, a calibration signal generator, coupled to the antenna interface, to inject a calibration signal at the antenna interface; wherein the digital compensator (212a-212c) is configured in accordance with signals received by the digital compensator (212a-212c) in response to injection of the calibration signal at the antenna interface; wherein the digital processor includes control instructions for controlling when the calibration signal generator injects the calibration signal at the antenna interface and for controlling configuration of the digital compensator (212a-212c) in accordance with the digitized received signals received in response to the injection of the calibration signal at the antenna interface, wherein the calibration signal produced by the calibration signal generator includes a time domain signal corresponding to orthogonal frequency components in a predefined range of frequencies, the duration or period of the time domain signal being equal to, or an integral multiple of, the inverse of the frequency spacing between the orthogonal frequency components, and that the digital compensator (212a-212c) is configured in accordance with phase values produced by a Fourier transform of signals received by the digital compensator (212a-212c) in response to injection of the calibration signal at the antenna interface, the Fourier transform producing the phase values for a plurality of frequencies corresponding to the orthogonal frequency components of the calibration signal, characterized in that the amplitude and duration of the calibration signal is determined in accordance with a criterion that the average power of the calibration signal is maintained lower than a value which would impact gain settings of a gain control circuit of the signal receiver. an antenna interface for receiving signals from an antenna; analog signal processing circuitry (208a-208c) coupled to the antenna interface for processing the received signals to produce filtered signals; sampling circuitry (210a-210c) to sample the filtered signals so as to produce digitized received signals; a digital compensator (212a-212c) to receive the digitized received signals and compensate for non-uniform group delay introduced by the analog signal processing circuitry (210a-210c) to produce compensated digitized received signals; and a digital processor to process the compensated digitized received signals so as to produce a result, a calibration signal generator, coupled to the antenna interface, to inject a calibration signal at the antenna interface; wherein the digital compensator (212a-212c) is configured in accordance with signals received by the digital compensator (212a-212c) in response to injection of the calibration signal at the antenna interface; wherein the digital processor includes control instructions for controlling when the calibration signal generator injects the calibration signal at the antenna interface and for controlling configuration of the digital compensator (212a-212c) in accordance with the digitized received signals received in response to the injection of the calibration signal at the antenna interface, wherein the calibration signal produced by the calibration signal generator includes a time domain signal corresponding to orthogonal frequency components in a predefined range of frequencies, the duration or period of the time domain signal being equal to, or an integral multiple of, the inverse of the frequency spacing between the orthogonal frequency components, and that the digital compensator (212a-212c) is configured in accordance with phase values produced by a Fourier transform of signals received by the digital compensator (212a-212c) in response to injection of the calibration signal at the antenna interface, the Fourier transform producing the phase values for a plurality of frequencies corresponding to the orthogonal frequency components of the calibration signal, characterized in that the amplitude and duration of the calibration signal is determined in accordance with a criterion that the average power of the calibration signal is maintained lower than a value which would impact gain settings of a gain control circuit of the signal receiver.