FIELD-DELINEATED ACOUSTIC WAVE DEVICE

• US 3,675,052 A
• Filed: 08/07/1970
• Issued: 07/04/1972
• Est. Priority Date: 08/07/1970
• Status: Expired due to Term

• Current Assignee: George F. Lindsay, Harper John Whitehouse
• Original Assignee: George F. Lindsay, Harper John Whitehouse
• Inventors: Lindsay, George F., Whitehouse, Harper John
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): Reynolds, B. A.
• Application Number:
  US05/062,117
• Time in Patent Office: 697 Days
• Field of Search: 340/3A,10 310/8.1,9.7,9.8 333/30,72
• US Class Current: 310/313.00B
• CPC Class Codes: G10K 11/36 Devices for manipulating acoustic surface waves electro-acoustic amplifiers H03F13/00; networks comprising electro-acoustic elements H03H9/00
• CPC Class Codes: H03H 9/02228 Guided bulk acoustic wave devices or Lamb wave devices having interdigital transducers situated in parallel planes on either side of a piezoelectric layer
• CPC Class Codes: H03H 9/02236 of surface skimming bulk wave devices
• CPC Class Codes: H03H 9/0296 Surface acoustic wave [SAW] devices having both acoustic and non-acoustic properties
• CPC Class Codes: H03H 9/60 Electric coupling means therefor H03H9/0095 takes precedence

Abstract

An acoustic wave device, wherein an applied electrical signal is transduced to an acoustic wave, comprising: a substrate capable of propagating the acoustic wave; a conductive structure disposed upon the substrate, including at least three separate conductive paths; a pair of the conductive paths including spaced-apart electrodes; and the third conductive path including fielddelineating electrodes which are disposed between the electrodes of the pair of paths. In more detail, each of the conductive paths of the acoustic wave device include electrodes in the form of parallel elements, linear or planar, disposed upon the substrate perpendicularly to the direction of surface wave propagation, caused by the application of an electrical voltage to the pair of conductive paths, which is transduced to an acoustic surface wave. The electrodes of each conductive path are spaced a distance nd apart, where n is an integer, n being equal to 1 for the spacing of the shielding electrodes. A bus at one end of the elements connects the set of elements of each respective conductive path.

Claims

1. An acoustic wave device comprising:

a substrate capable of propagating an acoustic wave;

a conductive structure disposed upon the substrate, including at least three separate conductive paths;

a pair of the conductive paths including spaced-apart, interdigitated, electrodes; and

the third conductive path including field-delineating electrodes which are interdigitated between the electrodes of tHe pair of paths;

the conductive paths including;

electrodes in the form of a set of parallel elements disposed upon the substrate substantially overlapping in a direction perpendicularly to the direction of surface wave propagation;

the electrodes of each conductive path being spaced a distance nd apart, where n is an integer, n being equal to 1 for the spacing of the field-delineating electrodes; and

a bus at one end of and connecting the set of elements of each respective conductive path.

2. An acoustic wave device according to claim 1, wherein the electrodes of each of the three conductive paths are spaced a uniform distance d apart.

3. An acoustic wave device according to claim 1, wherein not all of the electrodes of each of the pair of conductive paths are spaced a unit distance d apart, that is, the electrodes are interdigitated in a coded manner.

4. An acoustic wave device according to claim 3, wherein the conductive structure constitutes an output conductive structure;

and further comprising;

an input conductive structure disposed upon the substrate, adapted to transduce an electrical signal applied to it into an acoustic wave which propagates across the substrate.

5. An acoustic wave device according to claim 4, wherein the input conductive structure comprises a pair of conductive paths.

6. An acoustic wave device according to claim 5, wherein the pair of conductive paths for the input conductive structure comprise one element, or electrode, for each path.

7. An acoustic wave device according to claim 4, wherein the input and output conductive structures are identical, and correspond in configuration to one member of a Golay complementary pair;

and further comprising another input and output conductive structure, disposed upon the substrate parallel to the first-named input and output conductive structures, respectively, and configured to correspond to the second member of a Golay complementary pair.

8. An acoustic wave device according to claim 7, further comprising an isolator strip disposed between the members of the Golay complementary pair;

and an absorber stripe at each end of the substrate, disposed parallel to the electrodes.

9. An acoustic wave device according to claim 8, wherein the acoustic wave device is a surface wave device, wherein the substrate is a flat plate, capable of propagating a surface wave;

the electrodes are flat, parallel, linear elements disposed upon the surface of the substrate;

the busses are linear and disposed upon the surface of the substrate; and

the isolator strip and absorber stripes are flat, linear, and disposed upon the surface of the substrate.

10. An acoustic wave device according to claim 8, wherein the acoustic wave device is a volume wave device, wherein the substrate consists of right, rectangular, prismatic, segments, capable of propagating a volume wave;

the electrodes are rectangular, planar, parallel, surfaces disposed upon the surfaces of the segments of the substrate;

the busses are planar and disposed upon the surfaces of the segments of the substrate; and

the isolator strip and absorber stripes are rectangular, planar, surfaces disposed upon the surfaces of the segments of the substrate.