Li Lixia, He Weitao, Tong Zhixue, Liu Haixia, Xie Miaoxia
School of Mechanical and Electrical Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Institute of Mechanics, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Micromachines (Basel). 2022 Jul 29;13(8):1217. doi: 10.3390/mi13081217.
This paper presents a type of single-phase double "I" hole phononic crystal (DIH-PnC) structure, which is formed by vertically intersecting double "I" holes. By using the finite element method, the complex energy band curve, special point mode shapes, and different delay lines were calculated. Numerical results showed that DIH-PnC yielded ultra-wide band gaps with strong attenuation. The formation mechanism is attributed to the Bragg-coupled local resonance mechanism. The effects of the pore width in DIH-PnC on the band gaps were further explored numerically. Significantly, as the pore width variable, the position of the local resonance natural frequency could be modulated, and this enabled the coupling between the local resonance and the Bragg mechanism. Subsequently, we introduced this DIH-PnC into the thin-film piezoelectric-on-silicon (TPOS) resonator. The results illustrated that the anchor loss quality factor (Qanc) of the DIH-PnC resonator was 20,425.1% higher than that of the conventional resonator and 3762.3% higher than the Qanc of the cross-like holey PnC resonator. In addition, the effect of periodic array numbers on Qanc was researched. When the Qanc reached 1.12 × 10, the number of the period array in DIH-PnC only needed to be 1/6 compared with cross-like holey PnC. Adopting the PnC based on the coupling Bragg and local resonance band gaps had a good effect on improving the Qanc of the resonator.
本文提出了一种单相双“I”孔声子晶体（DIH-PnC）结构，它由垂直相交的双“I”孔构成。利用有限元方法，计算了复能带曲线、特殊点模态形状和不同的延迟线。数值结果表明，DIH-PnC产生了具有强衰减的超宽带隙。其形成机制归因于布拉格耦合局部共振机制。通过数值进一步探究了DIH-PnC中孔宽度对带隙的影响。值得注意的是，随着孔宽度变化，局部共振固有频率的位置可以被调制，这使得局部共振与布拉格机制之间能够耦合。随后，我们将这种DIH-PnC引入到薄膜硅基压电（TPOS）谐振器中。结果表明，DIH-PnC谐振器的锚固损耗品质因数（Qanc）比传统谐振器高20425.1%，比十字形多孔PnC谐振器的Qanc高3762.3%。此外，研究了周期阵列数量对Qanc的影响。当Qanc达到1.12×10时，DIH-PnC中周期阵列的数量与十字形多孔PnC相比仅需要1/6。采用基于布拉格和局部共振带隙耦合的PnC对提高谐振器的Qanc有良好效果。
