A Self-Sustained Frequency Comb Oscillator via Tapping Mode Comb-Drive Resonator Integrated with a Feedback ASIC

We report on the first experimental demonstration of a reconfigurable self-sustained MEMS oscillator that can generate either a stable single oscillation frequency output or a frequency comb consisting of a set of equally spaced frequency lines. The oscillator is built upon integrating a single-crystal (SC) silicon-on-insulator (SOI) comb-drive MEMS resonator with a programmable sustaining amplifier enabled by an application-specific integrated circuit (ASIC) in CMOS. The comb-drive MEMS resonator has a displacement stopper; and its first in-plane resonance mode (26.26 kHz) can be operated in linear, nonlinear, and `tapping' regimes, depending on the oscillation amplitude. The reconfigurable oscillator is controlled by finely tuning the operation regime of the resonator by applying a DC polarization voltage to the resonator and via gain of the ASIC. The system can generate either a stable single oscillation frequency or controllable frequency comb output over a wide frequency range with a spacing of ~0.8 to 2.6 kHz.