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. 28, 1996
Filed:
Apr. 21, 1995
Isao Takeuchi, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A frequency synthesizer includes a voltage-controlled oscillator, frequency dividing circuits, a signal source, phase comparing circuits, an adding circuit, a converting circuit and a control circuit. The frequency dividing circuits divide an output supplied thereto from the voltage-controlled oscillator with frequency-dividing ratios of 1/N and 1/(N+1) where N is an arbitrary integer. The signal source outputs a reference frequency signal. The phase comparing circuits phase-compare a signal divided by N supplied thereto from one frequency dividing circuit and a signal divided by (N+1) supplied thereto from another frequency dividing circuit and the reference frequency signal from the signal source. The adding circuit adds a signal which results from phase-comparing the reference frequency signal output from the phase comparing circuit and the signal divided by N and a signal which results from phase-comparing the reference frequency signal output from the phase comparing circuit and the signal divided by (N+1). The converting circuit converts an output from the adding circuit to a DC signal and supplies the same to the voltage-controlled oscillator. The control circuit controls frequency-dividing ratios of the frequency dividing circuits. The control circuit cyclically changes the frequency-dividing ratios of the frequency dividing circuits to 1/N or 1/(N+1).