Intermittent phase locked loop frequency synthesizer for frequency hopping radio system
US4868523A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 21, 1988 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Jun 21, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/199
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency synthesizing apparatus comprising a reference generator (1) and a phase locked loop containing a phase detector (3) of the sample-hold type, a loop filter (4) a VCO (5) and a frequency divider (6) in the loop. The frequency divider (6) can be set at different numbers (N) so that the VCO sends different frequencies. In accordance with the invention a synchronizing unit (2) is connected between the reference generator (1) and the phase detector (3). The synchronizing unit switches reference generator (1) and the frequency divider means simultaneously to the phase locked loop during the locking phase and switches these out during a working phase, when the VCO (5) sends an output signal of the desired frequency (f). The loop filter can then be dimensioned with a wide bandwidth for rapid locking.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.