| 摘要 |
PURPOSE:To obtain a stable surface acoustic wave resonator where no resonance frequency is decreased even at the use of a long period by constituting a metallic strip constituting a reflector aluminum including silicon as an impurity. CONSTITUTION:An interdigital electrode 32 where a couple of comb tooth electrodes 32a, 32b are meshed with each other is formed on a piezoelctric substrate 31. The electrode 32 converts an input electric signal applied to an input terminal IN into a surface acoustic wave propagating on the surface of the substrate 31. Grating reflectors 33, 34 for reflecting the surface acoustic wave are formed on the substrate 31 at both sides of the electrode 32. Many metallic strips having strip width of lambda/4 are arranged in the reflectors 33, 34 at a period of lambda/2 pitch and all the reflected waves are applied in the same phase. No deterioration is caused to the strips even if the resonator is used for a long period by constituting the metallic strips of the reflectors 33, 34 with aluminum including silicon as an impurity and the surface acoustic wave resonator with stable and less change of resonance frequency is attained. |
