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:
Dec. 17, 1985
Filed:
Jan. 04, 1983
Jose I Suarez, Miami, FL (US);
James S Irwin, Ft. Lauderdale, FL (US);
Wayne P Shepherd, Sunrise, FL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A frequency synthesizer is provided including a reference frequency generator coupled to one input of a phase detector. The output of the phase detector is coupled via a pair of alternatingly connected filters through a voltage controlled oscillator and a divider circuit to the remaining input of the phase detector to form a phase locked loop. The first filter of the pair is designated for operation on a main channel frequency while the remaining filter is designated for operation on a priority channel frequency. The capacitive elements of each respective filter remain fully charged up for operation on their respective frequencies and thus when such filters are alternately switched between to change frequency from the main channel to the priority channel, the capacitive elements need not be charged to new levels to accommodate such frequency change. Thus, switching between a main channel and a priority channel is accomplished in a minimal amount of time with a significant reduction in frequency synthesizer energy requirements.