Circuit arrangement for frequency modulation
AssigneeAtmel Automotive GmbH
InventorAndreas Hanselmann
Life of this patent
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Abstract
A circuit arrangement for frequency modulation is provided, which includes a voltage-controlled oscillator having at least one varactor diode that is driven by a drive signal, wherein a capacitance of the varactor diode depends on the drive signal, includes a modulating unit that creates a modulation signal for frequency modulation of the voltage-controlled oscillator, and includes a drive unit that generates the drive signal for the at least one varactor diode from the modulation signal, wherein the drive unit generates the drive signal from the modulation signal in such a manner that a linear relationship results between the modulation signal and the capacitance of the varactor diode.
Claims7
A circuit arrangement for frequency modulation comprising:
- a voltage-controlled oscillator having at least one varactor diode that is driven by a drive signal, a capacitance of the varactor diode being dependend on the drive signal;
- a modulating unit that creates a modulation signal for frequency modulation of the voltage-controlled oscillator;
- and
- a drive unit that generates the drive signal for the at least one varactor diode from the modulation signal;
- wherein the drive unit includes a component whose current versus voltage characteristic curve is a second order polynomial and generates the drive signal based on the modulation signal so that a linear relationship results between the modulation signal and the capacitance of the at least one varactor diode.
A circuit arrangement for frequency modulation comprising:
- a voltage-controlled oscillator having at least one varactor diode that is driven by a drive signal, a capacitance of the varactor diode being dependend on the drive signal;
- a modulating unit that creates a modulation signal for frequency modulation of the voltage-controlled oscillator;
- and
- a drive unit that generates the drive signal for the at least one varactor diode from the modulation signal,
- wherein the drive unit generates the drive signal based on the modulation signal so that a linear relationship results between the modulation signal and the capacitance of the at least one varactor diode,
- wherein the drive unit includes a MOS transistor wired as a diode or an NMOS transistor wired as a diode, and
- wherein a resistor is connected in parallel to the MOS transistor wired as a diode.
Dependencies are inferred from the claim text.