| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave element small in size and having a stable temperature characteristic and an excellent surface acoustic wave propagation characteristic by forming a metal film for exciting, receiving and reflecting a surface acoustic wave on a single crystal substrate cut out from langanite single crystal. SOLUTION: A metal film pair of comb-shaped electrodes, i.e., an electrode 30 for excitation and a receiving electrode 40 are formed on a single crystal substrate 10 cut out from langanite (La3Ga5.5Nb0.5O14) single crystal and further sound absorption material layers 50 are formed at both end parts of the substrate 10. When a high frequency electric signal is inputted to the electrode 30 for excitation, a surface acoustic wave is excited by the substrate 10 to reach the electrode 40 and the high frequency electric signal is outputted. A frequency characteristic between these input and output has a bandpass filter characteristic and a filter characteristic and a temperature characteristic are decided by the surface acoustic wave propagation characteristic of the substrate 10. Also, because the langanite single crystal has a stable characteristic to temperature, the substrate 10 also has a stable temperature characteristic.
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