Abstract: The signal receiver has means to suppress at least one higher harmonic component from a MEMS or crystal oscillator having a reference resonator in filtered intermediate signals of a signal receiver. The signal receiver comprises an antenna for receiving electromagnetic signals, a low noise amplifier for amplifying signals received by the antenna, one MEMS or crystal oscillator comprising a reference resonator to generate an oscillating signal with a predefined duty-cycle, a mixer for mixing the amplified and received signals with the oscillating signal to generate intermediate signals, a band-pass filter to filter the intermediate signals, and a duty-cycle controller coupled to the MEMS or crystal oscillator and coupled to the output of the band-pass filter to analyze the spectrum of the filtered intermediate signals and to modify the duty-cycle of the oscillating signal in response to the spectrum analysis of the filtered intermediate signals.