2-d range hopping spread spectrum encoder/decoder system for RF tags
US7071866B2 · kind B2 · utility
6Cited by
15References
27Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 26, 2004 |
| Grant date | Jul 4, 2006 |
| Priority date | — |
| Expiry date | Oct 17, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/90
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An airborne radar interrogates tags on friendly ground vehicles, which when interrogated by a downlink signal from the radar, sends back a very low level uplink message signal that appears noise-like so as to avoid enemy detection and exploitation. This is achieved by retransmitting a time delayed and phase shifted version of the transmitted pulse from the radar. The digital RF tag captures every other pulse from the radar and transmits a digitally coded spread spectrum pulse back to the radar during every other intervening pulse which includes a pseudo random delay (range hop) and a pseudo random phase (direction).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.