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:
Mar. 22, 1983
Filed:
Mar. 04, 1981
Applicant:
Inventor:
Francis H Hilbert, Addison, IL (US);
Assignee:
Motorola Inc., Schaumburg, IL (US);
Primary Examiner:
Int. Cl.
CPC ...
H04H / ; H03D / ;
U.S. Cl.
CPC ...
179 / ; 329112 ; 329124 ; 455209 ; 455260 ;
Abstract
The circuit determines whether an incoming frequency is within the normal 'lock-in' range of a phase locked loop VCO or not, and whether it is higher or lower than the VCO frequency. If not within normal range, the beats are rectified and gated to provide a DC control voltage of the proper value and polarity for locking the oscillator on the incoming frequency. Rectification may be half or full wave as needed, and the circuit may include filter bandwidth control as well. This circuit is suitable for signals of any waveform, quadrature signals, and AM stereophonic signals.