Saw device tapped delay line and equalizer
US5051709A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1989 |
| Grant date | Sep 24, 1991 |
| Priority date | — |
| Expiry date | Jul 20, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/76
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A SAW device tapped delay line includes an apodized input IDT (inter-digital transducer) and a plurality of substantially identical unapodized output IDTs arranged to receive, after delays which successively increase by an amont T, a SAW propagated from the input IDT. Each output IDT is terminated with a low impedance which is constituted by the low input impedance of a buffer amplifier, to minimize acoustic regeneration by the output IDTs. Grounded dummy fingers with the same metallization ratio as the output IDTs are provided between adjacent output IDTs to provide a constant SAW velocity. The delay line is particularly suited to use in an equalizer of a microwave radio transmission system, in which the delay T is the inverse of the symbol rate of the system. Intermediate frequency automatic time domain equalizer (IF ATDE) arrangements using the SAW device tapped delay line are described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.