Abstract: A bulk acoustic wave delay line adapted to increase triple-transit signal suppression by selective aperture limiting, the device including a bulk acoustic wave-supporting body having a planar end face at each end of the bulk acoustic wave propagation path, the device also including an annular absorbing structure disposed on at least one of the end faces immediately adjacent to and surrounding a transducer for absorbing the portion of the propagating bulk acoustic wave energy impinging on an end face not covered by the transducer.

Abstract: A mode-converting type bulk acoustic wave delay line adapted to suppress triple transit signals and provide response tailoring, the device including a body of acoustic wave supporting material with at least one mode-converting planar surface capable of reversably converting longitudinal wave mode acoustic energy to shear wave mode acoustic energy, the device also including an attenuating structure disposed on the mode-converting planar surface for absorbing a predetermined amount of propagating shear wave mode energy and thereby increase insertion loss.

Abstract: A surface acoustic wave device useful as a notch filter or a narrow-band transmission filter, the device including a periodic metallic grating disposed on a suitable surface acoustic wave supporting substrate in a beam path defined by an input transducer, the grating elements each exhibiting energy storage discontinuities at the extremities thereof.

Abstract: A temperature stable surface acoustic wave device utilizing reflective gratings in a material such as Y-cut quartz having two propagation directions in which the temperature coefficients of delay are of opposite sign, the gratings reflecting the Rayleigh waves in the two propagation directions along suitable path lengths to provide a total linear zero temperature coefficient of delay. A temperature stable oscillator is formed by providing an amplifier in a feedback path from the output transducer to the input transducer of the surface acoustic wave device.

Abstract: A surface acoustic wave filter including a relatively broad band input transducer that launches acoustic energy along a first path, at least one frequency-selective periodic grating filter disposed in the first path and adapted to reflect the energy incident thereon along an intermediate path, at least one frequency selective periodic grating filter disposed in the intermediate path and adapted to reflect the energy incident thereon along an output path to an associated output transducer.