| 摘要 |
PURPOSE:To attain a surface acoustic wave resonator with excellent mass- productivity by making the width of at least a metallic strip or slot of a reflector different from a part of the metallic strip or slot. CONSTITUTION:The titled resonator consists of a piezoelectric substrate 1, and reflectors 3, 4 comprising a comb-line electrode 2 and a metallic strip. Distances lambda0, lambda1, lambda3 of the metallic strip are represented by a wavelength of the surface acoustic wave device to a resonance frequency f0. The relation of lambda0=V/f0X (V is the sound velocity in the substrate) is established. Further, the lambda1 is lambda0/4 and the lambda2 is nearly lambda0/8. Since the metallic strip (distance lambda2) suppressing a spurious reflecting wave in the photolithographic process is gener ated at the same time when the metallic strip (distance lambda1) generating a standing wave is generated in this way, the excellent mass-productivity is attained, and generation mistake in the sound absorbing layer or exfoliation of the sound absorbing layer is avoided, then the yield or the effect of improvement in the reliability are obtained. |
