Surface-wave transducer device and identification system with such device
US6788204B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2000 |
| Grant date | Sep 7, 2004 |
| Priority date | — |
| Expiry date | Mar 2, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R23/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention relates to a surface-wave transducer device—also called TAGs—and to identification systems with this device.DE 42 17 049 discloses a passive surface sensor which can be interrogated in wireless mode. In this context, energy is transmitted by radio to the sensor using an interrogation device, the interrogation being done by means of chirped transmission signals. The sensor has transducers and reflectors. The reflectors reflect the chirp signal in a time-staggered sequence, so that the sensor returns a time-staggered chirp signal to the interrogation device. The reflection principle means that the surface-wave sensor described above (also called SAW—surface acoustic wave—sensor in the following text) has a very high insertion loss of the order of 50 dB, for example. When the chirp signal has been received by an SAW interdigital transducer as the input transducer, this transducer produces a surface wave which propagates on the substrate of the SAW arrangement in the direction of the reflectors. When an SAW is received, each individual reflector element returns a correspondingly reflected SAW to the SAW transducer, which for its part produces an el…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.