Surface acoustic wave device
US6483402B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 2000 |
| Grant date | Nov 19, 2002 |
| Priority date | — |
| Expiry date | Dec 27, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/6433
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention provides a surface acoustic wave filter having an unbalance-to-balance conversion function and an impedance conversion function. This surface acoustic wave filter includes a piezoelectric substrate, a first surface acoustic wave filter that is made up of input and output interdigital transducers (IDTs), and a second surface acoustic wave filter that is also made up of input and output IDTs. The phase difference between the first surface acoustic wave filter and the second surface acoustic wave filter is approximately 180°. The input IDT of the first surface acoustic wave filter is connected to the input IDT of the second surface acoustic wave filter by a connecting wire, and a terminal extending from this connecting wire serves as an unbalanced terminal. An output terminal extends from the output IDTs of the first surface acoustic wave filter that are not connected to the second surface acoustic wave filter, and another output terminal extends from the output IDTS of the second surface acoustic wave filter that are not connected to the first surface acoustic wave filter. These output terminals constitute a balanced terminal 35.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.