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. 21, 2006
Filed:
Sep. 25, 2003
Tsuneo Mishima, Kyoto, JP;
Tetsuya Kishino, Kyoto, JP;
Hideharu Kurioka, Kyoto, JP;
Kyocera Corporation, Kyoto, JP;
Abstract
There is disclosed a variable capacitance circuit which comprises: first to Nth variable capacitance elements C-CN (N is an odd number) sequentially connected in series between an input terminal I and an output terminal O, whose capacitances change depending on voltage applied thereto; an ith bias line on the input terminal side provided between an input terminal portion of the first variable capacitance element and a connection point between a 2ith variable capacitance element and a (2i+1)th variable capacitance element; and an ith bias line on the output terminal side provided between an output terminal portion of the Nth variable capacitance element and a connection point between a (2i−1)th variable capacitance element and the 2ith variable capacitance element, where N and i are integers satisfying N=2n+1, n≧1, 1≦i≦n. With the arrangement of the variable capacitance circuit, it is possible to provide a variable capacitance thin film capacitor device whose capacitance change ratio is small in a radio frequency region and large in a direct current region can be provided. Furthermore, a radio frequency device utilizing the variable capacitance thin film capacitor device can be provided.