Authors: K.H. Nygaard, C. Grinde, T.A. Fjeldly
Affilation: Norwegian University of Science and Technology, Norway
Pages: 478 - 480
Keywords: RF MEMS, disk resonator, coupled resonators, modeling, simulation, fabrication
A novel, stacked coupled-disk resonator design is presented where the silicon discs vibrate in radial contour modes, actuated by electrodes wrapped around the disk periphery. The self-aligned, central stem mediates the coupling and also anchors the stack to the substrate. Operating identical discs in the fundamental mode, their acoustic nodes are located at the center, and the coupling strength is determined by the stem diameter, which therefore determines the resonance splitting. We consider a device with a disk diameter of 36 um operating near 150 MHz. A lumped element model is used to describe the device, incorporating only the most significant factors that determine the system response. The modeling is verified by means of FEM simulations. These simulations also serve as a guide for our resonator design. Energy dissipation and the Q-factor are described by an axis symmetric half space with a layer matched to the central stem. The resonator is presently being fabricated in our laboratories and the self-aligned fabrication procedure is described.