Apparatus for collecting and processing messages transmitted at different signal frequencies
US4479249A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 5, 1981 |
| Grant date | Oct 23, 1984 |
| Priority date | — |
| Expiry date | Nov 5, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/1851
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus for receiving messages transmitted from a plurality of radio signal sources operating at different frequencies within a predetermined frequency band. Means are provided to frequency scan the receive signals, deriving information for determining the frequency range in which said signals lie. A demodulating phase locked loop is connected to receive the radio frequency signals, and an initial operating frequency for the phase locked loop is provided by the frequency range information determined from the means for frequency scanning. A resetting circuit is included to maintain the phase locked loop oscillator frequency at a value independent of the frequency of the radio signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.