Surface acoustic wave device including parallel connected main and sub-filters
US6462633B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 12, 2001 |
| Grant date | Oct 8, 2002 |
| Priority date | — |
| Expiry date | Jan 12, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/14505
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A band filter is provided which can freely set the bandwidth and blocking characteristic without any need for a high level designing and adjustment. To this end, a surface acoustic wave device is so constructed as to connect a main filter Fm and sub-filter Fs in a parallel array. Here, relative to a frequency area corresponding to a passband of the main filter Fm the frequency-attenuation amount characteristic of the sub-filter Fs has a blocking band and, relative to a slope portion formed outside a passband of the main filter Fm, the frequency-attenuation characteristic of the sub-filter Fs has a rising area constituting a passband and signals involved provide an opposite-phase relation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.