Apparatus for low power radio communications
US6223061A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1997 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Jul 25, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus for low power radio communication comprising a transmitter having a frequency synthesizer and transmit antenna such that the frequency synthesizer comprises a phase locked loop circuit with a voltage controlled oscillator having a variable frequency output and with a loop filter/sample and hold circuit that allows opening of the synthesizer control loop and with special means of limiting the resulting frequency drift in the open loop state. The transmitter produces an output signal and the loop filter/sample and hold circuit holds the voltage controlled oscillator substantially on frequency such that the output signal remains stable, with a minimum of frequency drift, over a period of time when the phase lock loop synthesizer is set to an open loop state to allow frequency modulation unimpeded by the normal frequency correcting action of the synthesizer and for the frequency synthesizer to be partially powered down to reduce power consumption. The frequency modulation is linearized over a band of interest and undesired frequency shift at the initiation of modulation is suppressed. Receiver having automatic frequency control is included to extend the open loop transmit …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.