Oscillator crosstalk compensation

A method of mitigating a crosstalk signal in an output signal of a controlled oscillator of a victim phase-locked loop resulting from crosstalk between a controlled oscillator of an interfering phase-locked loop and the controlled oscillator of the victim phase-locked loop, comprising:

• generating a compensation signal at an offset frequency that is approximately equal to an offset between an output frequency of the controlled oscillator of the victim phase-locked loop and an output frequency of the controlled oscillator of the interfering phase-locked loop;
• and
• applying the compensation signal to the controlled oscillator of the victim phase-locked loop such that the output signal of the controlled oscillator of the victim phase-locked loop is modulated by the compensation signal;
• wherein an amplitude and phase of the compensation signal are such that, when the compensation signal is applied to the controlled oscillator of the victim phase-locked loop, the crosstalk signal in the output signal of the controlled oscillator of the victim phase-locked loop resulting from the crosstalk from the controlled oscillator of the interfering phase-locked loop to the controlled oscillator of the victim phase-locked loop is mitigated;
• wherein the controlled oscillator of the victim phase-locked loop is a controlled LC oscillator comprising a resonant tank comprising an inductor and one or more capacitors, and applying the compensation signal to the controlled oscillator of the victim phase-locked loop comprises switching a capacitor of the one or more capacitors in the resonant tank of the controlled LC oscillator with the compensation signal.

A wireless device, comprising:

• a first phase-locked loop comprising a first controlled LC oscillator comprising a first resonant tank comprising an inductor and one or more capacitors and adapted to provide an output signal at a first frequency;
• a second phase-locked loop comprising a second controlled LC oscillator comprising a second resonant tank comprising an inductor and one or more capacitors and adapted to provide an output signal at a second frequency;
• and
• a compensation signal generator adapted to:
• generate a compensation signal at an offset frequency that is approximately equal to an offset between the first frequency and the second frequency;
• and
• apply the compensation signal to the first controlled oscillator by switching a capacitor of the one or more capacitors in the first resonant tank of the first controlled LC oscillator such that the output signal of the first controlled oscillator is modulated by the compensation signal;
• wherein an amplitude and phase of the compensation signal are such that, when the compensation signal is applied to the first controlled oscillator, a crosstalk signal in the output signal of the first controlled oscillator resulting from crosstalk from the second controlled oscillator of the second phase-locked loop to the first controlled oscillator of the first phase-locked loop is mitigated.