Injection locking using direct digital tuning
US6963249B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 2003 |
| Grant date | Nov 8, 2005 |
| Priority date | — |
| Expiry date | Oct 16, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B5/1243
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention relates to the field of electronics and more particularly to the tuning and injection locking of voltage controlled oscillators (VCOs). An improved injection locking circuit is provided which allows the VCO to injection lock with a smaller reference signal and therefore a smaller locking bandwidth (LBW). In order to allow the VCO to injection lock with a lower power reference signal, this invention includes a pre-tuning algorithm to place the VCO frequency such that the desired frequency is in the LBW. Tuning of the VCO is achieved using direct digital tuning that does not require an input reference. Injection locking is performed using a low frequency clock harmonic as the reference signal. More specifically, tuning is accomplished by sub-sampling and digitizing the output signal of the VCO, determining the center frequency, and adjusting the VCO control voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.