Abstract
This work investigates a self-sustained phononic comb Micro-Electro-Mechanical Systems (MEMS) oscillator with comb control by using loop phase tuning. The formation of the phononic combs in this work is carried out through a self-oscillation (closed-loop) at the nonlinear state of a piezoelectric flexure mode resonator without any external parametric pumping. We experimentally confirm the tunability of the phononic combs by adjusting the loop phase (θT) of the Phase Lock Loop (PLL) in the lock-in amplifier at various oscillation points. The first two eigenmodes of the fully clamped thin-film resonator are adopted to demonstrate the proposed mechanism. Each of the eigenmodes is successfully sustained for oscillation by the use of the lock-in amplifier, thus featuring different phononic comb states. The achievement in this work could be further extended to frequency comb-based sensor technologies.