×

Systems and methods for maintaining a drive signal to a resonant circuit at a resonant frequency

  • US 8,022,775 B2
  • Filed: 10/08/2009
  • Issued: 09/20/2011
  • Est. Priority Date: 10/08/2009
  • Status: Active Grant
First Claim
Patent Images

1. A system for maintaining a drive signal to a resonant circuit at a resonant frequency comprising:

  • an oscillator configured to provide an output to a phase comparator and a drive circuit, the drive circuit configured to provide a drive signal to a resonant circuit;

    a phase detector configured to receive a filtered version of the drive signal by sensing a voltage at a junction of an inductor and a capacitor of the resonant circuit and provide a phase-indicating signal to the phase comparator; and

    the phase comparator, wherein the phase comparator is configured to provide a signal based on a phase difference between the oscillator output and the phase-indicating signal, wherein the signal from the phase comparator is used to control the frequency of the oscillator such that the phase difference converges to a fixed value.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×