UHF micromechanical extensional wine-glass mode ring resonators

Abstract

Vibrating polysilicon micromechanical ring resonators, utilizing a unique extensional wine-glass mode shape to achieve lower impedance than previous UHF resonators, have been demonstrated at frequencies as high as 1.2-GHz with a Q of 3,700, and 1.47-GHz (highest to date) with a Q of 2,300. The 1.2-GHz resonator exhibits a measured motional resistance of 560 k/spl Omega/ with a dc-bias voltage of 20 V, which is 6/spl times/ lower than measured on radial contour mode disk counterparts at the same frequency, and which can be driven down as low as 2 k/spl Omega/ when a dc-bias voltage of 100 V and electrode-to-resonator gap spacing of 460 /spl Aring/ are used. The above high Q and low impedance advantages, together with the multiple frequency, on-chip integration advantages afforded by electrostatically-transduced /spl mu/mechanical resonators, make this device an attractive candidate for use in the front-end RF filtering and oscillator functions needed by wireless communication devices.