Voltage-controlled oscillator and method for using the same
AssigneeSTMicroelectronics S.r.l.
InventorsGiuseppe Papotto, Alessandro Parisi, Andrea Cavarra, Giuseppe Palmisano
Life of this patent
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Abstract
A voltage controlled oscillator (VCO) includes: a pair of inductors coupled in series; a first pair of varactors coupled in series, and a second pair of varactors coupled in series. A first common mode node is between the respective varactors of the first pair of varactors and a second common mode node is between the respective varactors of the second pair of varactors. A supply voltage node is switchably coupled to the first common mode node through a first switch, the supply voltage node being a node located between the pair of inductors. A control voltage node (VC) is switchably coupled to the second common mode node through a second switch.
Claims20
A voltage controlled oscillator (VCO) circuit comprising:
- a pair of inductors coupled in series;
- a first pair of varactors coupled in series, a first common mode node being between the respective varactors of the first pair of varactors;
- a second pair of varactors coupled in series, a second common mode node being between the respective varactors of the second pair of varactors,
- a first terminal of the first pair of varactors being coupled to a first terminal of the second pair of varactors and a first terminal of the pair of inductors, and
- a second terminal of the first pair of varactors being coupled to a second terminal of the second pair of varactors and a second terminal of the pair of inductors;
- and
- a supply voltage node switchably coupled to the first common mode node through a first switch, the supply voltage node being a node located between the pair of inductors.
A voltage controlled oscillator (VCO) circuit comprising:
- a resonant circuit comprising a first pair of varactors and a second pair of varactors, a resonant frequency of the resonant circuit depending on a first capacitance of the first pair of varactors and a second capacitance of the second pair of varactors, the resonant frequency setting an output frequency of the VCO circuit;
- an oscillator core coupled to the resonant circuit;
- and
- a switching circuit configured to operate the VCO circuit in a first operating mode and a second operating mode, the switching circuit being configured to select the first pair of varactors for tuning the resonant frequency over a first frequency band in the first operating mode, and the switching circuit being configured to select the second pair of varactors for tuning the resonant frequency over a second frequency band outside the first frequency band in the second operating mode.
A method of operating a voltage controlled oscillator (VCO) circuit, the method comprising:
- operating the VCO in a first operating mode using a switching circuit, the VCO circuit comprising a resonant circuit comprising a first pair of varactors, a second pair of varactors, and a resonant frequency setting an output frequency of the VCO, the switching circuit setting the first pair of varactors to tune the resonant frequency over a first frequency band in the first operating mode;
- and
- operating the VCO in a second operating mode using the switching circuit, the switching circuit setting the second pair of varactors to tune the resonant frequency over a second frequency band outside the first frequency band in the second operating mode.
Dependencies are inferred from the claim text.