Abstract: An acoustic surface wave filter device for use in video IF stages in television receivers and the like, which comprises a substrate of a piezoelectric material and a spaced pair of transducers each of which is composed of a pair of interleaved comb type electrodes. One of the transducers is designed so as to have a frequency response curve in which attenuation poles at the both sides of the main lobe thereof, respectively, occur at frequencies corresponding to the upper adjacent-channel picture carrier frequency and the lower adjacent-channel sound carrier frequency. The other of the transducers is designed so as to have a frequency response curve in which the bandwidth thereof corresponds to the width from the sound carrier frequency of the associated channel to the lower adjacent-channel sound frequency. The substrate may be provided with a piezoelectric resonator. The substrate may be further provided with at least one ancillary transducing element.

Abstract: An elastic surface wave filter having a substrate of piezoelectric material and input and output transducer electrodes of interleaved-comb-type rigidly mounted on one surface of the substrate. The substrate is steadily supported in position within a casing by means of elastic support means which are made of synthetic or natural rubber material and which support means not only act as supporting instruments for the substrate, but also as vibration absorbing instruments for substantially suppressing unnecessary wave propagation through the substrate.