Quality Factor Enhancement of Piezoelectric MEMS Resonator Using a Small Cross-Section Connection Phononic Crystal

Abstract

Anchor loss is usually the most significant energy loss factor in Micro-Electro-Mechanical Systems (MEMS) resonators, which seriously hinders the application of MEMS resonators in wireless communication. This paper proposes a cross-section connection phononic crystal (SCC-PnC), which can be used for MEMS resonators of various overtone modes. First, using the finite element method to study the frequency characteristics and delay line of the SCC-PnC band, the SCC-PnC has an ultra-wide bandgap of 56.6–269.6 MHz. Next, the effects of the height h and the position h1 of the structural parameters of the small cross-connected plate on the band gap are studied, and it is found that h is more sensitive to the width of the band gap. Further, the SCC-PnC was implanted into the piezoelectric MEMS resonator, and the admittance and insertion loss curves were obtained. The results show that when the arrangement of 4 × 7 SCC-PnC plates is adopted, the anchor quality factors of the third-order overtone, fifth-order overtone, and seventh-order overtone MEMS resonators are increased by 1656 times, 2027 times, and 16 times, respectively.

An Investigation of the Energy Harvesting Capabilities of a Novel Three-Dimensional Super-Cell Phononic Crystal with a Local Resonance Structure

“…The coupling system provides a useful exploration method for vibration and sound suppression, acoustic hypersensitivity, energy location identification and the harvest of the elastic wave. On account of the research interests previously mentioned, numerous PnC structures are proposed in this article to improve energy-harvesting efficiency [ 9 , 10 , 11 ].…”

H-Shaped Radial Phononic Crystal for High-Quality Factor on Lamb Wave Resonators

“…Pandey et al designed a mesa around the resonator to reflect the elastic energy back to the resonator [ 18 ]. Using the band gap characteristics of phononic crystals (PCs) to suppress the anchor loss has attracted the attention of researchers [ 3 , 11 , 15 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. For example, Zhu et al used a two-dimensional stomatal PCs unit cell to increase the Q to twice the original [ 11 ].…”

“…Ardito et al used a one-dimensional PCs structure to increase the Q by several times [ 24 ]. Other shapes, such as rings [ 27 ], cross-like holes [ 13 ], fractals [ 14 ], Spider Web-Likes [ 15 ], cross-section connections [ 25 ], double “I” holes [ 26 ], and snowflakes [ 28 ] have also been reported. At present, Yinjie Tong has increased the Q of Pillar-Based PCs by 54% in the UHF range [ 3 ].…”

“…Shi et al designed different two-dimensional radial periodic structures to achieve low-frequency band gaps [ 34 ]. The usual design for one-dimensional PCs is to arrange them on the LWR support tether or in a two-dimensional arrangement on the anchor [ 15 , 16 , 19 , 22 , 25 , 26 , 27 , 35 , 36 , 37 , 38 , 39 ]. In the case of one-dimensional PCs, they are often arranged periodically along the x -axis on the support tether [ 16 , 22 , 35 , 36 , 37 , 38 , 39 ].…”

“…Therefore, one-dimensional PCs can effectively block the propagation of sound waves only by satisfying the directional band gap on the Г-X, but they also require a longer support tether to arrange PCs. Two-dimensional PCs are often arranged periodically on the anchor along the x -axis and y -axis [ 15 , 19 , 22 , 25 , 26 , 27 , 35 , 38 ]. Due to the arrangement of two-dimensional PCs, to effectively block the propagation of acoustic waves it is necessary to have directional band gaps along the Г-X, X-M, and M-Г directions of the irreducible Brillouin zone to achieve omnidirectional band gaps.…”