Loading patent…
AssigneeFraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
InventorsZhigong Wang, Manfred Berroth
Estimating the term…
A circuit for clock recovery from an input signal, particularly an alternating input signal formed from a data signal, the invention calling for a filter/amplifier unit made up of several series-connected resonance ampliers to be formed in a regenerative frequency filter. Unlike series-connected resonance amplifiers without feedback, the filter/amplifier unit has an overall Q-factor in the feedback loop which increases essentially linearly with the number of resonance amplifiers and their Q-factor. This enables the required high overall Q-factor to be obtained for the clock-recovery circuit with a relatively low number of resonance amplifiers with a Q-factor which is low compared with the overall Q-factor. A slope detector, a frequency mixer and the resonance amplifiers have similar assemblies so that the circuit can be designed more simply as a solid-state integrated circuit.
An apparatus for clock recovery from an alternating-voltage-carrying input signal which is formed from a digital data signal, said apparatus comprising a frequency mixer, said frequency mixer having first and second inputs and first and second outputs, said first input supplied with a signal that is assigned the clock frequency of an alternating-voltage-carrying input signal, and a filter and amplifier means for amplifying a narrow-band frequency range of an output signal of said frequency mixer, said filter and amplifier means including a filter and amplifier element having a high overall integrity, a feedback line transmitting an output signal of said filter and amplifier means to said second input of said frequency mixer, said filter and amplifier means including at least two series-wired filter and amplifier elements which comprise resonance amplifiers having tank circuits with inductances of monolithically integrated design, said resonance amplifiers having a low integrity as compared to the overall integrity of said filter and amplifier means, whereby the filter and amplifier means has high overall integrity and is formed of the cascaded resonance amplifiers, and is suited for amplification of a narrow-band frequency range of the output signal of the frequency mixer.
Dependencies are inferred from the claim text.