techRxiv_electrode_effects.pdf (985.05 kB)

Electrode Effects in mmWave Frequency Multilayer Bulk Acoustic Wave Resonators

Download (985.05 kB)
posted on 2023-04-24, 14:51 authored by Wenhao PengWenhao Peng

Electrodes are placed in acoustic resonators to set electrical boundary conditions, and they inevitably are acoustically part of the structure for a bulk acoustic wave (BAW) resonator that affect both its electromechanical coupling coefficient and its quality factor. In this work, a modal analysis is performed to obtain a closed-form expression for electromechanical coupling coefficient from material constants. The impact on electromechanical coupling coefficient effects due to the characterstic acoustic impedance of electrodes is observed in half wavelength per layer structures. Thermoelastic damping (TED) has been identified as the dominant acoustic loss mechanism in conductors. In this work, acoustic quality factors due to TED for common metals in  microelectromechanical systems (MEMS) processing are calculated to facilitate the observation of the quality factor effects of electrodes. It is observed that there are different strengths among characteristic acoustic impedance, acoustic quality factor, and electrical conductivity in different electrode metals.


Email Address of Submitting Author

ORCID of Submitting Author


Submitting Author's Institution

University of Michigan

Submitting Author's Country

  • United States of America