New design of RF MEMS disk resonators and optimization for spurious modes

A new more reliable design of micromechanical radial contour mode disk resonator have been demonstrated with the ability to work at UHF range and high quality factor in both vacuum and air and spurious modes free. In addition, this structure is capable to work at higher modes (e.g. second mode) without increasing the insertion loss and therefore lowering Q. These characteristics are achieved because of the ring shape anchor which placed at the nodal ring of resonator at the second mode. Also the ring shape anchor seems to be more reliable than stem shape anchor reported at previous papers. The motional resistance of the resonator is decrease due to displacement of the electrodes in both inside and outside of the structure. In addition to providing simulation results, this paper study the spurious modes heavily and optimize the inner radius to far spurious modes from fundamental mode without increasing the insertion loss. Transfer function and resonance frequency versus inner radius are also studied.