高Q值横向激发体声波谐振器的设计与制备

Design and Preparation of High-Q XBARs

随着5G移动通信时代的发展,射频前端(RF front-ends)的滤波和信号处理迫切需要高频大带宽的声学谐振器。横向激发体声波谐振器(XBAR)具有超高的工作频率和超大的机电耦合系数(k^(2)),但其品质因数(Q)值不高,阻碍了其在射频前端中的应用。该文提出了一种基于ZY切铌酸锂(LiNbO 3)的XBAR谐振器,通过有限元(FEM)仿真对谐振器进行了优化设计,并在微机电系统(MEMS)工艺下对谐振器进行加工。该文所制备的横向激发体声波谐振器A 1模式的谐振频率为4.72 GHz,k 2=26.9%,Q_(3) dB为384,温度频率漂移系数为-60.5×10^(-6)/℃。A_(3)模式的谐振频率为13.5 GHz,k^(2)=4.4%。

With the adventof the fifth generation(5G)mobile communication era,there is an urgent demand for high-frequency and large-bandwidth acoustic resonators for RF front-end filtering and signal processing.The laterally excited bulk wave resonator(XBAR)has garnered significant attention from researchers due to its ultra-high operating frequency and substantial electromechanical coupling coefficient(k 2).However,XBARs suffer from alow quality factor(Q),impeding their application in RF front-ends.This paper proposes XBARs based on ZY-cut lithium niobate(LiNbO 3).Resonator designs were optimized using the finite element method,and resonators were fabricated using micro-electro-mechanical systems.The resulting XBAR exhibiteda resonant frequency of 4.72 GHz,k^(2) value of 26.9%,Q_(3) dB value of 384,and temperature coefficient of frequency of-60.5×10^(-6)/℃for the A1 mode,along with a resonant frequency of 13.5 GHzand k^(2) value of 4.4%for the A_(3) mode.