Lorentz force transduction for RF micromechanical filters

This paper reports experimental results on use of Lorentz-force transduction for RF micromechanical filters. Use of Lorentz-force transduction involves significant lower motional resistance compared to electrostatic methods. Clamped-clamped microbeams (ccμm) fabricated in CMOS35, PolyMUMPs, and UW-MEMS are driven electrodynamically and characterized for their transduction performance. Derived by Laser vibrometer mode-shapes and resonance characteristics of these microstructures as well as electrical measurements provide data for motional resistance computations. These results show the significantly lower motional resistance of the electrodynamically driven microresonators due to the larger electromechanical coupling. Furthermore, Lorentz-force driving of ccμm resonators to higher modes up to 9^th. mode is demonstrated.