Radio frequency-based proximity detection system
US8279077B1 · kind B1 · utility
10Cited by
2References
29Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 3, 2009 |
| Grant date | Oct 2, 2012 |
| Priority date | — |
| Expiry date | Mar 30, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B21/0275
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A detection system includes a base station and a sensor. The base station defines a detection area and is configured to transmit a detection signal at a first frequency. The base station is further configured to facilitate selective variation of the detection area. The sensor is configured to detect the detection signal and transmit a communication signal at a second frequency in response to the detection signal. Movement of the sensor between the detection area and an area outside of the detection area affects detection of the detection signal. The first frequency is less than the second frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.