摘要 |
PURPOSE: To suppress spurious radiation appearing in the vicinity of an anti- resonance frequency without a thick electrode film thickness. CONSTITUTION: The interdigital transducer(IDT) surface acoustic wave resonator is provided with a piezoelectric substrate 61, an IDT 62 formed on the piezoelectric substrate 61, an input terminal 63 and an output terminal 64. The IDT 62 is configured with lots of pairs of interdigital electrodes to which rhombic shaped weighting is applied. Electrode fingers of the interdigital electrodes are arranged at a pitch ofλ/2 in the propagation direction of a surface acoustic wave in any of a surface acoustic wave stimulation section and a dummy electrode section. Furthermore, the electrode fingers are formed so that a relative position between an electrode finger stimulation section located to a surface acoustic wave stimulation section (s) and an electrode finger dummy electrode located in a dummy electrode section (d) is deviated byλ/8 in the propagation direction of the surface acoustic wave.
|