Robust control of oscillating NEMS sensors

To foster the advent of miniaturized, self-controlled and highly sensitive nanoelectromechanical systems, a model for electromechanical resonator operation under the control of an adaptative phase locked loop is presented. The implications of limited observability, due to detectability thresholds and noise, on start-up and oscillation stability are analysed. Minimum system requirements, necessary for proper oscillation, are defined and a strategy for robust system design, under the constraint of finite real-world bandwidths, finally crystallizes.