Patent ID: 7639757
Filing Date: 2009-12-29
Classification: H03M

Abstract:
1. A drive circuit for a micromechanical resonator, which has at least one pulse modulator for conversion of a complex input signal to a pulsed signal, and which has: a subtraction stage which produces a control error signal from the difference between the complex input signal and a feedback signal; a signal conversion stage, which converts the control error signal to a control signal; a first multiplication stage, which multiplies the control signal by a complex mixing signal oscillating at the frequency ω a quantization stage, which quantizes at least one of the real part and imaginary part of the control signal which has been up-mixed by ω a feedback unit, which uses the pulsed signal to produce the feedback signal for the subtraction stage, said first multiplication stage having a first multiplier for the in-phase signal path and a second multiplier for the quadrature signal path, with the first multiplier multiplying the real part of the control signal by the real part of the complex mixing signal oscillating at the frequency ω the pulse modulator has an adder which adds the first result signal from the first multiplier and the second result signal from the second multiplier to form a sum signal in order to determine the real part of the up-mixed control signal.