RF MEMS Resonator

Junjun Huan

Resonators for Timing and Frequency Control

• Quartz-crystal filters• Ceramic filters• SAW( surface acoustic wave) filters• Micromechanical filters

Silicon MEMS Resonators

• Economic reasons• Substantial size and power reduction• Long term stability: crystalline material

with a uniform, regular atomic structure• On-chip building blocks • Conceived capable of implementing

virtually any signal processing function presently realizable via transistor circuits

A micromachined, single-crystalsilicon, tunable resonator

• A fully integrated, single-crystal silicon (SCS) micromachined tunable resonator

• Natural resonant frequency of nominally 1 MHz • A room temperature quality factor approaching 10,000 in vacuu

m• Fully compatible with VLSI technology.

A micromachined, single-crystalsilicon, tunable resonator

A 12MHz Micromechanical Bulk Acoustic Mode Oscillator

• Longitudinal mode• Resonance frequency

12MHz• Q=180000• d=1µm

Lame-mode Square Resonator

Lame-mode Square Resonator

Square-Extensional Mode SCS Micromechanical Resonator

• Resonance frequency around 13.1MHz• High quality factor: Q=130000• High power handling capability: current out

put imax≈ 160µA• Vibration mode: a square plate zooming in

and out thus preserving the original shape• T-type corner anchoring to minimize energ

y leak to the substrate

Square-Extensional Mode SCS Micromechanical Resonator

MIDIS Process• MIDIS: MEMS Integrated Design for Inertial Sensors by Teledyne D

ALSA Semiconductor Inc. (TDSI)• 3 single crystal silicon wafers• TSVs: In-Situ Doped Polysilicon (ISDP) and silicon dioxide

Ring Resonator Model

Design Variables