Ring around transceiver
US4903324A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 1, 1988 |
| Grant date | Feb 20, 1990 |
| Priority date | — |
| Expiry date | Feb 1, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/005
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The communications system of the present invention defines a complete feedback path consisting of first and second transceivers and an appropriate signal path. Each transceiver comprises a detector and a signal source capable of generating a signal at one of two frequencies. The detector in each of the transceivers is a two state device tuned to respond only to a predetermined desired difference frequency. If the desired difference frequency signal is present, the detector provides and output signal in a first state; if the desired difference signal is not present, the detector provides an output signal which is in a second state. The signal source can be a voltage controlled oscillator, a pair of single frequency oscillators, a synthesizer, or any signal source capable of being electrically switched between two frequencies. Data can be exchanged between the transceiver pair only when the desired difference frequency is present.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.