1.52-GHz micromechanical extensional wine-glass mode ring resonators

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 55; no. 4; pp. 890 - 907
• Main Authors: Yuan Xie, Sheng-Shian Li, Yu-Wei Lin, Zeying Ren, Nguyen, C.T.-C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustics; Applied sciences; Circuit properties; Devices; Electric potential; Electric, optical and optoelectronic circuits; Electrical resistance measurement; Electronics; Exact sciences and technology; Filtering; Frequency measurement; Fundamental areas of phenomenology (including applications); General equipment and techniques; Impedance; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Micromechanical devices; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Optical ring resonators; Physics; Radio frequency; Resonator filters; Resonators; Shape; Transducers; UHF measurements; Ultrasonics, quantum acoustics, and physical effects of sound; Voltage; Wireless communication; Wireless communications; Wireless telecommunication; Polycrystal; Glass; Microwave; Microwave filter; Chip; UHF wave; Ring resonator; Bias voltage; Polysilicon; Microwave resonator; Frequency filtering; High frequency; Microstructure; Vibrational mode; Multiple frequency; Microelectromechanical device; Radio communication
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2008.725

Vibrating polysilicon micromechanical ring resonators, using 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 1.52 GHz with a Q of 2,800. The 1.2-GHz resonator exhibits a measured motional resistance of 1 MOmega with a dc-bias voltage of 20 V, which is 2.2 times lower than the resistance measured on radial contour- mode disk counterparts at the same frequency. The use of larger rings offers a path toward even lower impedance, provided the spurious modes that become more troublesome as ring size increases can be properly suppressed using methods described herein. With spurious modes suppressed, the high-Q and low-impedance advantages, together with the multiple frequency on-chip integration advantages afforded by capacitively transduced mumechanical resonators, make this device an attractive candidate for use in the front-end RF filtering and frequency generation functions needed by wireless communication devices.