Differential LC voltage-controlled oscillator
US6469587B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 2000 |
| Grant date | Oct 22, 2002 |
| Priority date | — |
| Expiry date | Dec 4, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2200/0038
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A differential voltage-controlled oscillator (VCO) employs a pair of accumulation-mode varactors driven with a differential control voltage to generate a differential oscillating waveform. The differential control voltage is formed from a pair of level-shifted input differential control voltage components. Level shifting of the input control voltages and driving the varactors with a differential control voltage allows for biasing of the varactors over a substantial range of capacitance variation. Such differential VCO may be employed within a phase-locked loop (PLL) circuit, with the pair of input control voltages being provided by the loop filter of the PLL circuit. The differential VCO comprises a differential control voltage to voltage converter (CV2VC) coupled to an LC-tank VCO. To improve common-mode noise rejection of the LC-VCO, the inductors of the LC-tank may be AC-coupled to the supply voltage, and the output differential oscillating waveform may be AC-coupled to the LC-tank through capacitors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.