Circuit for measuring the resonance frequency of nanoresonators

In the field of nanoresonator oscillators or NEMS (nanoelectromechanical systems) oscillators, a circuit is proposed for measuring the oscillation frequency of a resonator, including a phase-locked loop with a frequency-controlled oscillator and a phase comparator. The resonator includes a vibration excitation input and a dynamic polarization input (using strain gauges). The frequency-controlled oscillator applies a polarization frequency f1 to the polarization input. A frequency generator supplies a fixed intermediate frequency FI; a mixer receives the frequencies f1 and FI for producing an excitation frequency f0 that is the sum or difference of f1 and FI. The phase comparator receives the frequency FI and the output signal of the resonator and produces a control signal that is sent to the frequency-controlled oscillator, indirectly locking the oscillation frequency onto the resonant frequency of the resonator.