ACOUSTIC SURFACE WAVE DEVICES

• US 3,678,305 A
• Filed: 02/05/1971
• Issued: 07/18/1972
• Est. Priority Date: 02/06/1970
• Status: Expired due to Term

• Current Assignee: Edward George Sydney Paige
• Original Assignee: Edward George Sydney Paige
• Inventors: Paige, Edward George Sydney
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): Reynolds, B. A.
• Application Number:
  US05/113,010
• Time in Patent Office: 529 Days
• Field of Search: 310/8,8.1,9.5,9.7,9.8,8.2 317/235AG,235AH,246 333/30,72 330/5,5.5 315/3.5
• US Class Current: 310/313.00B
• CPC Class Codes: H03F 13/00 Amplifiers using amplifying element consisting of two mechanically- or acoustically-coupled transducers, e.g. telephone-microphone amplifier
• CPC Class Codes: H03F 3/54 Amplifiers using transit-time effect in tubes or semiconductor devices parametric amplifiers H03F7/00; solid state travelling-wave devices H10N70/10
• CPC Class Codes: H03H 9/02543 Characteristics of substrate, e.g. cutting angles
• CPC Class Codes: H03H 9/145 for networks using surface acoustic waves
• CPC Class Codes: H03H 9/42 using surface acoustic waves devices for manipulating acoustic surface waves in general G10K11/36
• CPC Class Codes: H04R 17/08 signals being recorded or played back by vibration of a stylus in two orthogonal directions simultaneously

Abstract

An acoustic surface wave device relies on its effectiveness not on the piezoelectric effect but on the electrostrictive effect whereby the effectiveness of the device is electric field dependent.

Claims

1. An acoustic surface wave device which relies on its effectiveness on the electrostrictive effect rather than on the piezoelectric effect whereby the effectiveness of the device is electric field dependent, said device comprising a body of material which has electrostrictive constants and piezoelectric constants such that for an acoustic surface wave traveling in a first given direction in said body and an electric field applied to said body in a second given direction the piezoelectric effect is negligible, and means for applying an electric field to the body of material in the second given direction.

2. An acoustic surface wave device as claimed in claim 1 in which the device is a one finger pair transducer.

3. An acoustic surface wave device as claimed in claim 1 in which the device is an interdigital comb transducer.

4. An acoustic surface wave device as claimed in claim 3 in which the means for applying an electric field to the body of material in the second direction includes means for applying variable electric fields to separate portions of the electrodes of said interdigital comb transducer.

5. An acoustic surface wave device as claimed in claim 1 in which the body of material includes a layer of said material on a substrate.

6. An acoustic surface wave device as claimed in claim 5 in which the thickness of said layer is no greater than two wavelengths in the material of an acoustic surface wave, said substrate being made of material which is physically capable of supporting an acoustic surface wave.

7. An acoustic surface wave device as claimed in claim 3 in which the body of material includes a layer of the material on a substrate.

8. An acoustic surface wave device as claimed in claim 7 in which the thickness of said layer is no greater than two wavelengths in the material of an acoustic surface wave, said substrate being made of material which is physically capable of supporting an acoustic surface wave.

9. An acoustic surface wave device as claimed in claim 4 in which the body of material includes a layer of said material on a substrate.

10. An acoustic surface wave device as claimed in claim 9 and in which the thickness of the layer is at most two wavelengths in the material of an acoustic surface wave, said substrate being made of material which is physically capable of supporting an acoustic surface wave.

11. An acoustic surface wave device as claimed in claim 1 and in which which the device is an acoustic surface wave amplifier.