Crystal notch filter comprising discrete quartz crystals coupled to a trimmable RC bridging network
US5030934A · kind A · utility
4Cited by
6References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 5, 1989 |
| Grant date | Jul 9, 1991 |
| Priority date | — |
| Expiry date | Jul 5, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/542
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved crystal notch filter is disclosed with a large passband-to-stopband ratio. The filter has individual sections with discrete crystal devices. In one embodiment as a 55 MHz trap, the filter has a passband from about 50 MHz to about 212 MHz with a 1 KHz stop band about a center frequency that may be tuned by means of a laser-trimmed bridging resistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.