Mechanically-coupled CMOS-MEMS free-free beam resonator arrays with two-port configuration

Integrated CMOS-MEMS free-free beam resonator arrays operated in a standard two-port electrical configuration simultaneously with low motional impedance and high power handling capability centered at 10.5 MHz have been demonstrated by the combination of pull-in gap reduction mechanism and mechanically-coupled array design. The mechanical links (i.e., coupling elements) using short stubs connect each constituent resonator of an array to its adjacent ones at the high-velocity vibrating locations to accentuate the desired mode and reject all other spurious modes. A single second-mode free-free beam resonator with quality factor Q >; 2,200 and motional impedance R_m <; 150 kQ has been utilized to achieve mechanically-coupled resonator arrays in this work. In array design, a 9-resonator array has been experimentally characterized to have around 10X performance improvement on motional impedance and power handling as compared with that of a single resonator. In addition, two-port electrical configuration is much preferred due to its low feedthrough nature and high design flexibilities for future oscillator and filter implementation rather than its one-port counterpart.