Magnetically-excited flexural plate wave resonator

摘要

A flexural plate wave (FPW) resonator was constructed bynpatterning current lines on a silicon nitride membrane suspended on anrectangular silicon frame. Eigenmodes of the rectangular membrane werenexcited using Lorentz forces generated between alternating surfacencurrents and a static in-plane magnetic field. The magnetic fieldnstrength required for these devices can be achieved with small permanentnmagnets (≈1 cm3). Preferential coupling to a particularnmembrane mode was achieved by positioning current lines alongnlongitudinal mode antinodes. An equivalent-circuit model was derivednthat characterizes the input impedance of a one-port device and thentransmission response of a two-port device over a range of frequenciesnnear a single membrane resonance. Experiments were performed toncharacterize the effects of varying magnetic field, ambient gas, gasnpressure, and input power. To our knowledge, this is the firstnexperimental demonstration of a resonant FPW device