声表面波谐振器频率-温度行为分析

声表面波（SAW）器件以其优良的性能广泛应用于雷达、通讯和日常用品等领域。然而，随着器件工作频率的不断升高，温度对器件频率稳定性的影响也越来越严重。因此，研究声表面波器件的温度效应，并在变温情况下保持SAW器件的频率稳定性至关重要。本文采用增量型的拉格朗日方程分析受温度影响的声表面波频率漂移问题。用频率-温度系数（TCF）作为评价频率-温度行为的标准。设计了一个具有温度补偿层的双层SAW谐振器模型，降低了器件的频率-温度系数。通过尺寸优化，LiNbO3-AlN结构的SAW谐振器在25℃（参考温度）下的频率温度系数TCF接近0ppm/℃。SAW谐振器的波长为4μm，谐振频率为1214.9MHz。

Analysis of Frequency-Temperature Behavior of SAW Resonator

Surface acoustic wave (SAW) devices are widely used in radar, communication and daily consumption due to their excellent performance. However, as operating frequency of the SAW devices grows higher and higher, the influence of temperature variation on frequency stability becomes more serious. Thus it is crucial to study the frequency-temperature behavior of SAW devices and improve frequency stability of SAW devices under variable temperature condition. In this paper, the incremental Lagrange equations are used to analyze the frequency shift of SAW affected by temperature. The temperature coefficient of frequency (TCF) is usually regarded as an evaluation on temperature-frequency behavior. To reduce temperature coefficient of frequency, a two-layer SAW resonator model is proposed with a temperature compensation layer. After optimization, the TCF of the SAW resonator with LiNbO3-AlN structure approaches to 0 ppm/℃ at 25℃ (reference temperature). The resonance frequency of the SAW resonator is 1214.9MHz and the wavelength is 4μm.