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:
Feb. 27, 2007
Filed:
Oct. 15, 2004
Junichi Matsuura, Tokyo, JP;
Eiichi Kaminishi, Osaka, JP;
Noriyuki Fujita, Saitama, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
To provide a voltage controlled variable capacitor which can change a capacitance value thereof in a wide controlled voltage range and control the capacitance value easily with a high precision without complicating the circuit configuration thereof, and to provide a voltage controlled variable capacitor which can change a capacitance value thereof with a good linearity. The voltage controlled varactor is configured in a manner that varactors VCk, each formed by a series connection of a fixed capacitor Ck (k=1, 2, . . . , n) and a MOS transistor Mk of N channel type, are connected in parallel. The MOS transistors Mto Mn are configured in a manner that gate widths W are same but gate lengths Lto Ln are elongated sequentially (that is, L<L< . . . <Ln) so that the threshold voltages thereof are differentiated from one another.