Mechanical phase inversion for coupled lamé mode resonator array filters

This paper reports a novel mechanism for mechanical phase inversion in MEMS filters to overcome the effects of capacitive parasitics without using external electrical phase inverter circuits. A 29.6 MHz, 0.05% bandwidth and 44.4 MHz, 0.1% bandwidth Lame mode square-plate resonator filters are designed and fabricated to experimentally validate the feasibility of electrically or mechanically coupled silicon microfabricated resonator filters. The mechanical phase inversion mechanism and reported internal electrical phase inversion mechanism ^[1] enhances the design flexibility for MEMS resonator based filters and the principle can be extended to filters based on other resonator topologies.