Variable capacitance circuit, variable capacitance thin film capacitor and radio frequency device
US7002435B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2003 |
| Grant date | Feb 21, 2006 |
| Priority date | — |
| Expiry date | Sep 25, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/215
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
There is disclosed a variable capacitance circuit which comprises: first to Nth variable capacitance elements C1-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 pro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.