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AssigneeInstitut Francais du Petrole
InventorPatrick Coquerel
Estimating the term…
A device is provided for locking the frequency and phase of a signal to that of a signal imposed, of the phase locked type. It comprises a modulator mixing a signal whose frequency is proportional to that of a reference signal coming from an oscillator. The low frequency component of the combined signal (isolated by an integrator) is permanently applied to the oscillator to an input with relatively low sensitivity, for the fine corrections, and to a high speed loop comprising a storage element and an amplifier, through a switch controlled by a window comparator. The high speed loop is connected to a higher sensitivity input. The high speed loop only acts during the setting period, for bringing the control voltage of the oscillator back to close to the optimum voltage, the optimization being provided by the permanent loop.
A device for rapidly and with low nose locking the frequency of a signal to that of an imposed signal from a reference oscillator comprising a slaved oscillator whose oscillation frequency can be varied by application of a control voltage and a first feed-back loop for bringing the control voltage back to an optimum value for stabilizing the frequency of the slaved oscillator, the phase noise inherent in said first loop and its response speed being relatively low, further comprising, in parallel with the first feed-back loop, which is permanently closed, a second feed-back loop causing a much faster variation of the oscillation frequency of the slaved oscillator than that caused by the first loop and control means for closing said second loop intermittently as long as the voltage difference between the control voltage applied to the slaved oscillator and said optimum value is greater than a given threshold value, said second loop including voltage storage means.
Dependencies are inferred from the claim text.