We present an experimental study of the frequency scaling of the main, square-extensional mode in a piezoelectrically actuated plate resonator. The studied set consists of resonators of different plate sizes with identical anchors. The behavior of the square-extensional mode is analyzed using electrical impedance measurements and optical characterization of the mechanical vibration fields. The results reveal a detrimental anchor effect, where for certain plate sizes the square-extensional mode branch is split into two due to a coupled oscillation of the resonator plate and the anchors.
Lipiäinen, L., Jaakkola, A., Kokkonen, K., & Kaivola, M. (2012). Frequency splitting of the main mode in a microelectromechanical resonator due to coupling with an anchor resonance. Applied Physics Letters, 100(1), . https://doi.org/10.1063/1.3673558