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:
Jan. 27, 2009
Filed:
Jun. 03, 2005
Masayuki Yonekawa, Kasugai, JP;
Yasuhiro Korogouchi, Kasugai, JP;
Mayo Kitano, Kasugai, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A voltage control oscillation (VCO) circuit and an adjusting method for the same, which enables an adjustment for suppressing the dispersion of the output characteristic in spite of the manufacture-related dispersion of element characteristics, using a simple circuit configuration, are provided. A low-pass filterand a high-pass filterare composed of the elements that have the same structure as elements composing the VCO circuit, and a prescribed correlation is established between both elements. A corrective elementis connected in parallel to a main element, in which an oscillation frequency control signal VT is input, in the VCO circuit. Respective frequency-gain characteristic lines of the low-pass/high-pass filtersandhave gradients reverse to each other and cross at a target gain TG. When the capacitance value lowers in dispersion, the level of an output signal SLbecomes higher than that of an output signal SHat a reference frequency fREF to form an output level difference LD. In response, an adjusting signal VCNTis output in correspondence to the output level difference LDto lower an oscillation frequency fVCO.