Patent ID: 8774748

Claim:
A high sensitivity FSK radio frequency signal receiver, said receiver including: an antenna for receiving FSK radio frequency signals, at least one low noise amplifier for amplifying and filtering the signals picked up by the antenna, a local oscillator with a quartz resonator for supplying oscillating signals, at least one mixer unit for mixing the filtered and amplified incoming signals with the oscillating signals supplied by the local oscillator, in order to produce intermediate signals, whose frequency is equal to the difference between the frequency of the oscillating signals and a carrier frequency of the incoming signals, a broadband or polyphase filter for filtering the intermediate signals, and an intermediate signal sampler for supplying sampled intermediate signals to a high sensitivity demodulation stage, which supplies data signals, wherein the receiver also includes a processing and selection circuit, which is capable of performing at least one discrete Fourier transform on the basis of the sampled intermediate signals, in order to determine the difference between the frequency of a signal amplitude peak above a determined threshold and the expected frequency of the intermediate signals, to correct the frequency of the oscillating signals from the local oscillator, and arranged to demodulate the data from the sampled intermediate signals in the demodulation stage, wherein the high sensitivity FSK radio frequency signal receiver includes a selector at the output of the processing circuit, which receives one or several results per discrete Fourier transform of the sampled intermediate signals, which is performed in the processing circuit, and wherein said selector is arranged for checking the frequency error relative to the expected frequency of the intermediate signals, taking account of the positive and/or negative data modulation deviation in the sampled intermediate signals, and for supplying a control signal to the local oscillator to correct the frequency of the oscillating signals according to the determined frequency error.