Discrete amplitude calibration of oscillators in frequency synthesizers
US7570925B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 2006 |
| Grant date | Aug 4, 2009 |
| Priority date | — |
| Expiry date | May 18, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/18
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In one embodiment, this disclosure describes a frequency synthesizer for use in a wireless communication device, or similar device that requires precision frequency synthesis but small amounts of noise. In particular, the frequency synthesizer may include a phase locked loop (PLL) and an integrated voltage controlled oscillator (VCO). The frequency synthesizer may implement one or more amplitude calibration techniques prior to enabling the PLL. For example, an amplitude calibration unit may be used to selectively activate switched unit current sources within a tail current source of the VCO. In this manner, the amplitude the signal generated by the oscillator can be adjusted without requiring closed-loop amplitude monitoring or control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.