摘要
LiNbO3 has been found attractive for lateral field excitation （LFE） applications due to its high piezoelectric coupling. In this paper, bulk acoustic wave propagation properties for LiNbO3 single crystal excited by a lateral electric field have been investigated using the extended Christoffel Bechmann method. It is found that the LFE piezoelectric coupling factor for c mode reaches its maximum value of 95.46% when ψ = 0° for both （yxl）-58° and （yxwl）±60°/58° LiNbO3. The acoustic wave phase velocity of c mode TSM （thickness shear mode） changes from 3456 m/s to 3983 m/s as a function of ψ. Here ψ represents the angle between the lateral electric field and the crystallographic X-axis in the substrate major surface. A 5 MHz LFE device of （yxl）-58° LiNbO3 with ψ = 0° was designed and tested in air. A major resonance peak was observed with the motional resistance as low as 17 Ω and the Q-factor value up to 10353. The test result is well in agreement with the theoretical analysis, and suggests that the LFE LiNbO3 device can be a good platform for high performance resonator or sensor applications.
LiNbO3 has been found attractive for lateral field excitation （LFE） applications due to its high piezoelectric coupling. In this paper, bulk acoustic wave propagation properties for LiNbO3 single crystal excited by a lateral electric field have been investigated using the extended Christoffel Bechmann method. It is found that the LFE piezoelectric coupling factor for c mode reaches its maximum value of 95.46% when ψ = 0° for both （yxl）-58° and （yxwl）±60°/58° LiNbO3. The acoustic wave phase velocity of c mode TSM （thickness shear mode） changes from 3456 m/s to 3983 m/s as a function of ψ. Here ψ represents the angle between the lateral electric field and the crystallographic X-axis in the substrate major surface. A 5 MHz LFE device of （yxl）-58° LiNbO3 with ψ = 0° was designed and tested in air. A major resonance peak was observed with the motional resistance as low as 17 Ω and the Q-factor value up to 10353. The test result is well in agreement with the theoretical analysis, and suggests that the LFE LiNbO3 device can be a good platform for high performance resonator or sensor applications.
基金
supported by the National Natural Science Foundation of China (Grant No 60571014)
