Abstract: A withdrawal transducer structure is employed in a narrow-band surface acoustic wave device requiring many pairs of interdigital transducer fingers or in a high-frequency surface acoustic wave device in which the thickness of interdigital transducer fingers is large relative to the wavelength of the surface acoustic wave, so that the interdigital transducer fingers may not severely adversely affect the characteristics of the device. The interdigital transducer fingers in the input and output piezoelectric transducers are suitably partly omitted leaving some of them or dummy fingers are additionally provided to eliminate the adverse effect of the interdigital transducer fingers on the characteristics of the device, so that the narrow-band or high-frequency surface acoustic wave device can operate with improved performance without having any unnecessary frequency response.

Abstract: A surface acoustic wave (SAW) device includes a SAW element disposed on a printed circuit. The printed circuit has an insulation substrate having input and output wiring conductors and input side and output side grounding conductors formed thereon. Interdigital transducers of the SAW element are connected to the input and output wiring conductors. The input side grounding conductors and the output side grounding conductors are disposed apart from each other with an isolation gap inbetween, thereby obtaining desirable filtering characteristics by suppressing undesirable coupling between input side and output side caused by a feed through electromagnetic wave.