The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 24, 1990
Filed:
Mar. 28, 1989
Peter G Laws, Wiltshire, GB;
Graham J Fletcher, Wiltshire, GB;
Plessey Overseas Limited, Ilford, GB;
Abstract
A receiver circuit for data in NRZ1 coding transmitted at high data rates along optical fiber links, wherein in order to overcome problems of phase jitter in the incoming signal, a clock circuit is included comprising a phase locked loop with voltage controlled oscillator for generating a clock signal locked in phase to the incoming data signal, a phase detector for comparing the clock signal with the incoming data signal, a phase frequency detector for comparing the clock signal with a reference clock signal, a multiplexer for switching the phase locked loop to respond either to the output of the phase detector or the phase freqency detector, and a digital counting system for comparing the number of clock pulses generated in a reference period determined by the reference clock, the digital counting system controlling the multiplexer to switch to the output of the phase detector when it is determined that the clock signal is accurately following the reference clock signal.