Claims
- 1. An interactive acoustic structure comprising:
- a horizontal ledge having at least a top surface portion thereof made of piezoelectric material, said ledge extending outwardly from said substrate with the top surface portion of said ledge being coplanar with the top surface of said substate, said substate and said ledge defining an acoustic waveguide;
- means disposed on said substate for exciting a tightly confined acoustic wave in the ledge of said waveguide at one frequency;
- means disposed on said ledge for exciting an acoustic wave in said waveguide at a second frequency whereby said two frequencies will mix; and
- an output transducer on said waveguide responsive to one of the sum and difference of the two input frequencies.
- 2. An interactive acoustic structure as set forth in claim 1, wherein said means for exciting an acoustic wave in said waveguide at a second frequency comprises means for exciting an acoustic wave at said second frequency as a tightly confined mode.
- 3. An interactive acoustic structure as set forth in claim 1, wherein said means for exciting fan acoustic wave in said waveguide at a second frequency comprises an interdigital transducer having a transducer pad with a plurality of electrode fingers extending therefrom in a lateral direction toward the edge of said ledge.
- 4. An interactive acoustic structure as set forth in claim 1, wherein said output transducer comprises a transducer pad having a plurality of electrode fingers extending therefrom in a lateral direction toward the edge of said ledge.
- 5. An interactive acoustic structure comprising:
- a horizontal ledge acoustic waveguide including a substrate and a horizontal ledge extending outwardly therefrom;
- means for exciting a tightly confined acoustic Rayleigh wave in the ledge of said waveguide at one frequency, said means being arranged so that the Rayleigh wave is incident on said ledge obliquely near its center;
- means for exciting an acoustic wave in said waveguide at a second frequency whereby said two frequencies will mix; and
- an output transducer on said waveguide responsive to one of the sum and difference of the two input frequencies.
Parent Case Info
This is a division, of application Ser. No. 451,718, filed Mar. 14, 1974, and now U.S. Pat. No. 3,974,464.
US Referenced Citations (2)
Non-Patent Literature Citations (4)
Entry |
Davis et al--"Steering Acoustic Surface Waves by Nonlinear Mixing" in Applied Physics Letters, vol. 21, No. 7, Oct. 1, 1972; pp. 323-325. |
Lagasse et al--"Acoustic Surface Waveguides-Analysis and Assessment" in IEEE Trans. on Microwave Theory and Techniques vol. MTT 21, Apr. 1973; pp. 225-235. |
Mason et al--"Ridgeguides for Acoustic Surface Waves" in Electronics Letters, July 15, 1971, vol. 7, No. 14; pp. 395-397. |
Luukkala et al--"Convolution and Time Inversion Using Parametric Interactions of Acoustic Surface Waves" in Appl. Phys. Lett. vol. 18, No. 9, May 1, 1971; pp. 393-394. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
451718 |
Mar 1974 |
|