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:
Aug. 29, 1995
Filed:
Apr. 20, 1993
Hitachi, Ltd., Tokyo, JP;
Abstract
A frequency synthesizer which comprises a voltage controlled oscillator; a unit for outputting a value corresponding to a differential phase of a reference signal at a predetermined frequency as a first differential phase; a unit for sampling an oscillating signal corresponding to an output of the voltage controlled oscillator K times per period of a repeating frequency f.sub.r (f.sub.r is an arbitrary frequency) and for repetitively generating phase information of the oscillating signal in the form of saw-tooth-like wave; a unit for calculating the difference between adjacent phase information in phase information of the oscillating signal outputted as a saw-tooth-like wave, and for outputting this difference as a second differential phase; a comparator for calculating the difference between the first and second differential phases; a signal processing unit for integrating an output of the comparator; and a unit for converting an output of the signal processing unit to a voltage to control the voltage controlled oscillator.