This study reports the design of a novel Butterfly Lamb wave resonator (LWR) employing the S0 mode in the AlN plate, and for the first time, its ultrahigh parallel-resonance quality factor ( Qp ) of 4,021 is demonstrated, indicating an ultralow acoustic loss. Although the series resonance quality factor ( Qs ) is widely used for various loss comparisons, it is inconclusive since Qs is always dominated by the routing resistance ( Rs ), which is normally huge without the thick metal rewiring. Instead, Qp is a precise representation of the acoustic loss level for its independence of Rs and as it is closer to Qmax of the Bode Q -curve in the IDT-excited devices. A butterfly-shaped resonance cavity, theoretically predicted to reduce the anchor loss and suppress the transverse spurious mode, has been applied to the AlN LWR and experimentally shown to boost the Qp by 2.3 times. In addition, a directly measured Bode- Q curve for the LWR is reported for the first time, showing superior Q profile for the Butterfly-LWR than the conventional-LWR and good agreement with the 3 dB- Qp 's.

中文翻译：

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AlN板上的超低声损耗微加工蝴蝶兰姆波谐振器。

这项研究报告了在AlN板中采用S0模式的新型蝴蝶兰姆波谐振器（LWR）的设计，并且首次展示了其超高并联谐振品质因数（Qp）为4,021，表明超低声损耗。尽管串联谐振品质因数（Qs）广泛用于各种损耗比较，但是由于Qs始终由布线电阻（Rs）决定，因此不确定，因为布线电阻（Rs）通常很大，而无需重新布线厚金属。取而代之的是，Qp由于其Rs的独立性以及在IDT激励设备中更接近Bode Q曲线的Qmax而精确地表示了声损耗水平。从理论上讲，蝴蝶形谐振腔可减少锚固损耗并抑制横向杂散模式，已将其应用于AlN LWR，并通过实验证明可将Qp提高2.3倍。此外，首次报告了直接测量的LWR的Bode-Q曲线，显示出Butterfly-LWR的Q轮廓优于常规LWR，并且与3 dB-Qp吻合良好。