Phased array acoustic signal processor

• US 5,164,627 A
• Filed: 07/26/1988
• Issued: 11/17/1992
• Est. Priority Date: 07/26/1988
• Status: Expired due to Fees

• Current Assignee: Harris Corporation Melbourne
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Popek, Marc H.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US07/228,333
• Time in Patent Office: 1,575 Days
• Field of Search: 310/313 B, 333/193
• US Class Current: 310/313.00B
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals
• CPC Class Codes: G10K 11/346 using phase variation
• CPC Class Codes: H03H 9/40 Frequency dependent delay lines, e.g. dispersive delay lines H03H9/42 takes precedence

Abstract

A bulk acoustic signal processor for processing GHz range R.F. signals employs a transmitter array comprised of an apodized set of subdivided interdigital electrodes mounted on a bulk wave launching crystal, the apodization being defined by the shape of an aperture in a layer of dielectric material on the crystal, over which the electrodes extend into contact with the surface of crystal for stressing the crystal and launching an acoustic wave into the bulk on which the crystal is mounted. Because a respective subdivided set of interdigital electrode elements has an impedance on the order of 0.5 to 6 ohms, each set is driven by a dedicated, impedance-transforming GaAs FET source-follower amplifier. When driven by an R.F. input signal, the respective sets of driver electrodes launch a focused set of acoustic waves which effectively spatially combine with one another to form a directed bulk wave whose direction of travel in the bulk is proportional to the input frequency and whose intensity is sufficient to enable the input energy to be detected by a spaced apart receiver electrode array. The receiver electrode array, similar to its transmitter counterpart, is formed of a plurality of interleaved electrode layers or fingers which extend over the layer of dielectric atop the lithium niobate crystal and into a receiver array aperture in the dielectric layer into contact with the surface of the crystal.

Claims

1. A signal processing apparatus comprising:

an acoustic bulk;

first means, coupled to said acoustic bulk, for receiving information signals and for launching acoustic waves into said bulk and causing said acoustic waves to be dispersed through said bulk in accordance with the frequency contents of said information signals said first means comprising an acoustic wave generating medium mechanically coupled with said acoustic bulk, a multiplicity of electrode elements arranged in closely spaced relationship with one another on a first surface portion of said acoustic wave generating medium, a first plurality of signal drivers to which said information signals are coupled for application to said multiplicity of electrode elements, respective ones of the signal drivers of said first plurality being coupled to respectively adjacent first sets of first and second sets of electrode elements into which said multiplicity of electrode elements are subdivided, and a second plurality of signal drivers to which said information signals are coupled for application to said multiplicity of electrode elements, respective ones of the signal drivers of said second plurality being coupled to respectively adjacent second sets of electrode elements, and wherein the outputs of said first signal drivers are shifted in phase with respect to the outputs of said second signal drivers; and

second means, coupled to a prescribed information detection region of said acoustic bulk, for detecting dispersed acoustic waves that have been launched into said bulk by said first means and for providing an output representative thereof.

2. A signal processing apparatus according to claim 1, wherein said second means comprises an acoustic wave responsive medium mechanically coupled with said prescribed information detection region of said acoustic bulk and a multiplicity of electrode elements arranged in closely spaced relationship with one another on a first surface portion of said acoustic wave responsive medium.

3. A signal processing apparatus according to claim 1, wherein said acoustic wave generating medium is mechanically coupled with said prescribed information detection region of said acoustic bulk and said second means includes a multiplicity of electrode elements arranged in closely spaced relationship with one another on a surface portion of said acoustic wave generating medium that is coupled with said prescribed information detection region of said acoustic bulk.

4. A signal processing apparatus according to claim 1, wherein said first means further includes a dielectric layer selectively formed on said acoustic wave generating medium so as to have an aperture therein exposing said first surface portion of said acoustic wave generating medium on which the multiplicity of electrode elements of said first means are arranged in closely spaced relationship with one another, and first and second pluralities of signal conductors extending over said dielectric layer and being electrically coupled with said first and second pluralities of signal drivers, respectively.

5. A signal processing apparatus according to claim 4, wherein said acoustic wave generating medium is mechanically coupled with said prescribed information detection region of said acoustic bulk and said second means includes a multiplicity of electrode elements arranged in closely spaced relationship with one another on a surface portion of said acoustic wave generating medium that is coupled with said prescribed information detection region of said acoustic bulk.

6. A signal processing apparatus according to claim 5, wherein said second means further includes said dielectric layer selectively formed on that surface portion of said acoustic wave generating medium that is coupled with said prescribed information detection region of said acoustic bulk, so as to have an aperture therein exposing said that surface portion of said acoustic wave generating medium on which the multiplicity of electrode elements of said second means are arranged in closely spaced relationship with one another, and third and fourth pluralities of signal conductors extending over said dielectric layer and being electrically coupled with interleaved pluralities of the multiplicity of electrode elements of said second means.

7. A signal processing apparatus according to claim 6, wherein the shape of said aperture is contoured to define a prescribed apodization of the acoustic wave launched into said bulk.

8. A signal processing apparatus according to claim 1, wherein said signal drivers comprise field effect transistor buffer amplifier circuits coupled to said sets of electrodes in a source-follower configuration.

9. A signal processing apparatus according to claim 1, wherein the outputs of said first signal drivers are shifted in phase by 180 degrees with respect to the outputs of said second signal drivers.

10. A radio wave signal processing apparatus comprising:

an acoustic bulk;

first means, coupled to said acoustic bulk, for receiving radio wave signals having a frequency on the order of at least one GHz. and for launching acoustic waves into said bulk and causing said acoustic waves to be dispersed through said bulk in accordance with the frequency contents of said information signals, said first means comprising an acoustic wave generating medium mechanically coupled with said acoustic bulk, a multiplicity of sets of interdigital electrodes disposed on a first surface portion of said acoustic wave generating medium, a first plurality of impedance transforming signal drivers to which said radio wave signals are coupled for application to first sets of said multiplicity of electrode elements, respective ones of the signal drivers of said first plurality being coupled to respectively adjacent first sets of interdigital electrodes, and a second plurality of impedance transforming signal drivers to which said R.F. signals are coupled for application to second sets of said interdigital electrodes, respective ones of the signal drivers of said second plurality being coupled to respectively adjacent second sets of said interdigital electrodes, and wherein the outputs of said first signal drivers are effectively complementary to the outputs of said second signal drivers; and

second means, coupled to a prescribed information detection region of said acoustic bulk, for detecting dispersed acoustic waves that have been launched into said bulk by said first means and for providing an output representative thereof.

11. A signal processing apparatus according to claim 10, wherein said second means comprises an acoustic wave responsive medium mechanically coupled with said prescribed information detection region of said acoustic bulk and a plurality of interdigital electrodes disposed on a first surface portion of said acoustic wave responsive medium.

12. A signal processing apparatus according to claim 10, wherein said acoustic wave generating medium is mechanically coupled with said prescribed information detection region of said acoustic bulk and said second means includes a plurality of interdigital electrodes disposed on a surface portion of said acoustic wave generating medium that is coupled with said prescribed information detection region of said acoustic bulk.

13. A signal processing apparatus according to claim 10, wherein said first means further includes a dielectric layer selectively formed on said acoustic wave generating medium so as to have an aperture therein exposing said first surface portion of said acoustic wave generating medium on which the interdigital electrodes of said first means are disposed, and first and second pluralities of signal conductors extending over said dielectric layer and being electrically coupled with said first and second pluralities of impedance transforming signal drivers, respectively.

14. A signal processing apparatus according to claim 13, wherein said acoustic wave generating medium is mechanically coupled with said prescribed information detection region of said acoustic bulk and said second means includes a plurality of interdigital electrodes disposed on a surface portion of said acoustic wave generating medium that is coupled with said prescribed information detection region of said acoustic bulk.

15. A signal processing apparatus according to claim 14, wherein said second means further includes said dielectric layer selectively formed on that surface portion of said acoustic wave generating medium that is coupled with said prescribed information detection region of said acoustic bulk, so as to have an aperture therein exposing said that surface portion of said acoustic wave generating medium on which the plurality of interdigital electrodes of said second means are disposed, and third and fourth pluralities of signal conductors extending over said dielectric layer and being electrically coupled with interleaved ones of the plurality of interdigital electrodes of said second means.

16. A signal processing apparatus according to claim 15, wherein the shape of said aperture is contoured to define a prescribed apodization of the acoustic wave launched into said bulk.

17. A signal processing apparatus according to claim 15, wherein said signal drivers comprise field effect transistor buffer amplifier circuits coupled to said first and second sets of interdigital electrodes in a source-follower configuration.