Raytheon Company

Manfred B Schulz

Melvin G Holland

Frank Sandy

A surface acoustic wave low loss filter device having input and output transducers located along opposed sides of a rectangular propagation path with frequency selective reflective gratings at each of the four corners of the rectangle. Two traveling surface waves traverse the device along opposed paths encountering frequency filtering at the gratings. The two waves arrive at the output transducer additively in phase eliminating the bidirectionality loss normally associated with surface acoustic wave devices. At frequencies for which the gratings are reflective there can be nearly lossless transmission from input to output. At all other frequencies, transmission between input and output transducers is negligible. The device has high sidelobe rejection, adjustable passband skirt slopes, and an adjustable bandwidth.

Surface acoustic wave ring filter

A surface acoustic wave device having substantially all of the surface wave energy produced at an input transducer coupled to the output utilization means. Plural reflecting means upon the surface of a piezoelectric substrate reflect surface waves produced by the input transducer in plural directions. The passband characteristics of the device are determined by the interaction of the transfer properties of each of the reflecters as well as those of the input and output transducers. Devices are described having extremely low insertion loss and wide bandwidth with low sidelobes and steep passband skirts.

Wide band low loss acoustic wave device

A temperature compensated acoustic surface wave device, such as a surface wave delay line is provided in which temperature compensation is provided by the deposition of an interdigital electrode structure on a substrate with an overlay film surface of piezoelectric material of a predetermined thickness. A double substrate arrangement is also disclosed in which the interdigital electrode structure is deposited upon the surface of a non-piezoelectric layer which in turn is placed upon the surface of a piezoelectric substrate.

Temperature compensated acoustic surface wave device

A temperature compensated acoustic surface wave device, such as a surface wave delay line is provided in which temperature compensation is provided by the deposition of an interdigital electrode structure on a substrate with an overlay film surface of piezoelectric material of a predetermined thickness. A double substrate arrangement is also disclosed in which the interdigital electrode structure is deposited upon the surface of a non-piezo-electric layer which in turn is placed upon the surface of a piezoelectric substrate.

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Sudbury, MA, United States of America

Manfred B Schulz