Surface acoustic wave band pass filtering
US4044321A · kind A · utility
20Cited by
6References
37Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 1, 1976 |
| Grant date | Aug 23, 1977 |
| Priority date | — |
| Expiry date | Mar 1, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/1455
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Two piezoelectric filters are cascaded for suppression of bulk waves while mutually reinforcing surface wave band pass filtering. Each filter has an apodized central transducer and two outer transducers. In one instance the two outer transducers on one filter differ from the two outer transducers of the other filter with regard to bulk wave generation and reception. In another instance one filter provides asymmetric transmission and symmetry is restored by a wave slow-down for surface waves only. In still another instance the slow-down pad is provided also, but the signals in the two outer transducers are electrically inverted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.