Radio with fast lock phase-locked loop
US5175729A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1991 |
| Grant date | Dec 29, 1992 |
| Priority date | — |
| Expiry date | Jun 5, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/405
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A communication device (508) for use in a Time Division Multiplex (TDM) communication system (500) includes a transmitter, a receiver, and a frequency scanner for quickly scanning the radio frequency communication channels to determine an available channel. The communication device (508) also includes a phase locked loop (100) for providing a reference signal for the communication device (508) and locking to the available channel. This phase locked loop (100) includes a Voltage Control Oscillator (VCO) (104) having a control signal input (103). The phase locked loop (100) also includes a first filter (110) and a second filter (108). The first filter (110) has a wide frequency response. The second filter (108) includes a storage element (222) and has a narrow frequency response. The phase locked loop (100) also includes a switching circuit (106) which determines which one of the two filters (110, 108) gets coupled to the voltage control oscillator (104).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.