| 摘要 |
A SAW filter includes a piezoelectric substrate of a single crystal LiNbO3 and SAW resonators having an electrode thickness ranging from about 8% to about 9% of an acoustic wavelength of a high velocity SAW excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (lambda, mu, theta), with angle lambda in a range from -5° to +5°, angle mu in a range from about 75° to about 85°, and angle theta in a range from 85° to 95°. A metalization ratio for the resonators ranges from about 0.3 to about 0.9, with resonators in a parallel arm of the filter having a metalization ratio from 1.1-1.4 times larger than the metalization ratio for resonators in the series arm of the filter. Such orientations simultaneously combined with an optimized electrode thickness and optimized metalization ratios provide an improved performance in RF applications.
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