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:
May. 02, 1978
Filed:
Oct. 13, 1976
David E Sanders, St. Petersburg, FL (US);
Alfred T Anderson, St. Petersburg, FL (US);
Robert S Gordy, Largo, FL (US);
E-Systems, Inc., Dallas, TX (US);
Abstract
Apparatus for indicating a phase lock condition between an incoming multiphase carrier signal and a local oscillator in a phase-locked loop demodulator. A phase error signal is generated by phase comparing the carrier signal and the local oscillator signal. The phase error signal is rectified and the result detected for a range of values that indicate a phase lock condition. Phase lock exists when the phase error signal is within selected voltage ranges. After detection, the error signal is low-pass filtered and compared to a predetermined threshold value to generate a phase-lock indication signal. In the last two steps, an indication signal is generated to signify that the phase error signal is in the range of voltage values corresponding to phase lock for a greater percentage of time than it is within this range with the loop is not phase locked.