High-resolution, active reflector radio frequency ranging system
US8711032B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 2012 |
| Grant date | Apr 29, 2014 |
| Priority date | — |
| Expiry date | Sep 24, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2201/70715
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A radio frequency ranging system is grounded in establishing and maintaining phase and frequency coherency of signals received by a slave unit from a master unit and retransmitted to the master unit by the slave unit. For a preferred embodiment of the invention, coherency is established through the use of a delta-sigma phase-lock loop, and maintained through the use, on both master and slave units, of thermally-insulated reference oscillators, which are highly stable over the short periods of time during which communications occur. A phase relationship counter is employed to keep track of the fractional time frames of the phase-lock loop as a function of the reference oscillator, thereby providing absolute phase information for an incoming burst on any channel, thereby enabling the system to almost instantaneously establish or reestablish the phase relationship of the local oscillator so that it synchronized with the reference oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.