High frequency of micromechanical resonator via structural modification

In this paper, it presents an improvement over a simple free-free resonator via structural modification. Two modified designs have been considered and named as an Inverse-Pi and Inverse-T free-free beam micromechanical resonator, utilizing torsional-mode support springs. The operating range, according to the simulation is 90-130 MHz. This is a great improvement over its predecessor whose operating frequency is 30-90 MHz. Three main design aspect of this resonator are the modified structural design, the support beam structure and the operation parameter. In the former, the relationship between the natural frequency and resonator beam thickness, width and length are found to be interrelated. For the supporting structure design, the length of the supporting beam is determined by λ/4 based on torsional vibration studies. Finally, in the operation parameter, the pull down electrostatic force voltage of the transducer is determined. The experimental testing was done on an inverse-T structure and found that it conforms with the simulation result.