Stable Oscillation of Mems Resonators Beyond the Critical Bifurcation Point

Abstract

MEMS resonators have many useful features, but they can suffer performance limitations because of the limited linear range of motion of their micromechanical elements. Operation beyond the critical bifurcation limit is believed to cause significant instabilities and is generally discouraged [1]. However, the stability criterion for closed-loop oscillators differs from that for open-loop observation [2], thereby enabling operation of stable oscillators beyond the limit dictated by critical bifurcation. This paper describes the use of phase-controlled oscillators to prove stable operation beyond the critical bifurcation limit, which can directly improve the power handling capabilities of many micromechanical oscillators.

Influence of the A-F effect on the temperature stability of silicon micromechanical resonators

“…In a closed-loop measurement (Fig. 2b), however, instability does not arise, and large V ac for large A is favored for better signal-to-noise ratio [9]. Therefore, ∆f is not negligible, and f r = f 0 +∆f.…”

Nonlinear UHF quartz MEMS oscillator with phase noise reduction

“…Greywall and Yurke proposed taking advantage of nonlinearity in mechanical resonator to evade phase noise in a magnetically driven oscillator system [1,2]. Lee demonstrated stable oscillation of an electrostatic silicon MEMS resonator driven beyond the critical bifurcation point [3]. However, the demonstration was achieved at ~ 1 MHz carrier frequency.…”