Fast hopping frequency synthesizer using an all digital phased locked loop (ADPLL)
US7701997B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2007 |
| Grant date | Apr 20, 2010 |
| Priority date | — |
| Expiry date | May 10, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2001/71365
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A novel and useful fast hopping frequency synthesizer and transmitter associated therewith. The frequency synthesizer and transmitter incorporates a digitally controlled oscillator (DCO) adapted to operate open loop. Instantaneous frequency switching is achieved by changing an oscillator tuning word (OTW) to imitate the three oscillators of a UWB transmitter. In one embodiment, the DCO can change the frequency instantaneously within the 1/fT of the varactor devices used to construct the DCO. An all digital phase lock loop (ADPLL) is used for offline calibration prior to the start of packet transmission or reception. Any phase shift during the switching is tracked by a digital circuit in the transmitter. In a second embodiment, additional frequency accuracy is provided by use of a numerically controlled oscillator (NCO) that functions to generate a fine resolution complex exponential waveform which effectively shifts the synthesized frequency. A mixer applies the waveform to the I and Q data samples prior to conversion to the digital domain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.