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:
Jul. 01, 2008
Filed:
Sep. 17, 2004
Makoto Sasaki, Yokohama, JP;
Makoto Sasaki, Yokohama, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A PLL frequency synthesizer improves near C/N, shortens lockup time, and reduces residual FM. In this apparatus, an input current signal is converted to a voltage signal by one of a plurality of loop filters with different cutoff frequencies and output to a voltage controlled oscillator. An oscillation signal generated by the voltage controlled oscillator is branched at a first junction point and output to a frequency divider and an output terminal. A variable capacitance capacitor is connected to a second junction point branched subsequent to the first junction point and its capacitance is controlled in accordance with loop filter switching control of a control circuit.