Anchor loss in weakly coupled resonator systems of mode-localized sensor based on perfectly matched layer method

The performance of mode-localized sensors highly depends on the rate of vibrational energy dissipation, and anchor loss is one of the major dissipation sources for vacuum-encapsulated sensors. To study anchor energy loss in weakly coupled resonator systems, the Perfectly Matched Layer (PML) method is utilized to investigate the influence of key factors on the anchor loss quality factor of mode-localized sensors, including the size and position of the coupled beam, the resonator dimensions, and the material properties of weakly coupled resonator. The results indicate that increasing the ratio of Young's modulus between the substrate and resonator beam can improve the quality factor by approximately 7.4 times, enhancing the length-to-width ratio of the resonator beam can increase the quality factor by up to 14 times. Additionally, reducing the width of the coupled beam by 80 % doubles the quality factor. Moreover, the anchor loss is influenced not only by the local stress distribution near the substrate, but also increases with the eigenfrequency of the resonator, while changes in stiffness of equivalent dynamic stiffness alter the vibrational energy distribution at the anchor. These findings can provide valuable references for the design and optimization of mode-localized sensors.