Leland P. Solie - Acton MA William J. Tanski - Maynard MA
Assignee:
Sperry Corporation - New York NY
International Classification:
H03H 902 H03H 926 H03H 932 H01L 4110
US Classification:
333195
Abstract:
A multiple track acoustic surface wave filter processes input signals successively flowing in coupled resonant acoustic tracks, each track being realized between pairs of surface wave reflectors in the surface of a planar piezoelectric substrate.
Temperature Compensated Reflective Array For Surface Acoustic Wave Processing
An apparatus for processing surface acoustic waves includes input and output transducers mounted on a piezoelectric substrate so as to launch and receive acoustic waves, respectively. Two pairs of reflective arrays are positioned in the propagation path between the input and output transducers so as to provide an S-shaped propagation path in which the directions of propagation of the waves launched by the input transducer and received by the output transducer are essentially parallel.
An apparatus for processing acoustic signals wherein an array of discrete scatterers on a substrate reflect an incident acoustic surface wave on the substrate in accordance with a predetermined transfer function which is established by the size and spacing of the scatterers within the array. The scatterers, and input and output transducers, may all be metalized on the surface of the substrate with a single mask, thus providing an economical means of construction.
Apparatus for convolving acoustic surface waves without dispersion comprising a piezoelectric substrate having surface acoustic waves generated at opposite ends thereof and directed towards an interaction region formed from a semiconductor film deposited thereon. The film is deposited on the substrate at such an angle with respect to the direction of propagation of each of the two acoustic surface waves so that the dispersive components of the wave vectors associated with the surface acoustic waves refracted in the interaction region substantially cancel. Apparatus is also disclosed for substantially eliminating undesired wave reflections in a convolver operating in the degenerate mode wherein a conductive array of electrode fingers is disposed at an angle with respect to the direction of propagation of the acoustic surface waves such that the reflections therefrom are directed away from the paths traversed by said acoustic surface waves.
Surface Acoustic Wave Coupling With Respect To Non-Piezoelectric Substrates
A wide band surface wave transducer is provided with means for launching a surface acoustic wave on a non-piezoelectric material by first launching the surface wave at the surface of a piezoelectric material spaced apart from the aligned non-piezoelectric element. A mechanical coupling array provides energy transfer between the two wave propagating surfaces.
Three Wave Surface Acoustic Wave (Saw) Signal Processor
A surface acoustic wave processor capable of performing convolution, correlation, time expansion/compression, and time reversal utilizes the nonlinear interaction between two input surface waves to generate a third surface wave. Phase matching for the third surface wave to perform an integration function is provided by a fan multistrip coupler (FMSC) which appropriately alters the velocity of an electric field pattern transferred from one track of the FMSC to a second track thereof.
Temperature Insensitive Reflective Array S.a.w. Device
The invention provides a temperature-insensitive, reflective acoustic wave signal processor employing a trio or reflective arrays disposed effectively to rotate the direction of propagation of the acoustic wave through 180 angular degrees so that the acoustic wave in a preferred embodiment reaches the output transducer flowing in the opposite parallel direction as when launched by the input transducer.
A multistrip surface acoustic wave filter having directional coupling characteristics may be used to transfer acoustic wave energy between acoustic wave channels or tracks. The devices are characterized by predetermined signal filtering pass bands, since the degree of transfer of energy is made a function of the excitation frequency. The fanned multistrip surface wave filter elements may be cascaded or weighted to provide a range of design selectivity of frequency response.