Modulated backscatter sensor system
US6084530A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1996 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Dec 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/756
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A radio communication system includes an Interrogator for generating and transmitting a radio signal. One or more Tags contained within the radio communication system receive the radio signal. A Backscatter Modulator modulates the reflection of the radio signal using a subcarrier signal, thereby forming a reflected modulated signal. The Interrogator receives and demodulates the reflected modulated signal. Based upon the characteristics of the demodulated signal, the Interrogator can determine the identity of the Tag, and the relative velocity of the Tag with respect to the Interrogator. The Interrogator can also determine if motion exists in the vicinity of the Interrogator, even when no Tag is present, without the need for a separate motion detection system. The characteristics of the demodulated signal, can also be used to determine the characteristics of motion of the Tag, such as the vibrational frequency. Alternate embodiments allow the Interrogator to transmit a first information signal to one or more tags, specifying which Tags should respond using Modulated Backscatter, so that the characteristics of only particular Tags can be determined. Further alternate embodiments allo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.