Surface wave devices for differential coherent detectors
US5668431A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1996 |
| Grant date | Sep 16, 1997 |
| Priority date | — |
| Expiry date | Mar 7, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/72
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A surface wave device, for use in differential coherent detection in a commutation signaling communications system using N predetermined M-bit codewords, propagates surface waves for each codeword to a first coded output IDT (inter-digital transducer) comprising M parallel taps with a pitch t=T/M, the taps having phases representing bits of the respective codeword, and to a second output IDT which is at a distance from an input IDT greater by T than the first coded output IDT, to provide an additional delay of one information symbol. The input IDT, or each tap of each coded output IDT, has a length equal to t. The second output IDT can comprise a coded IDT, or a delay tap responsive to the surface wave propagated via the first coded output IDT.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.