Accession Number : ADD017364

Title :   Dual-Frequency Sonar System.

Descriptive Note : Patent Filed 8 Jan 93, patented 22 Nov 94,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Kelly, James G ; Walsh, Charles R

Report Date : 22 Nov 1994

Pagination or Media Count : 10

Abstract : A dua! frequency, polymer hydrophone, array for a submersible vehicle is disclosed. A mid-frequency transducer array is employed in the forward end of a submersible vehicle. between the mid-frequency array and a nose portion of the submersible vehicle is a single or multiple board piezoelectric polymer array employed to implement a secondary, high-frequency transducer array. Amplifying and signal conditioning units are mounted adjacent or on onc metallic electrode layer or formed integrally thereon to minimize signal lead loss. The piezoelectric polymer material is chosen to have a density coefficient and sound velocity substantially equivalent to an acoustic window in the nose portion of the submersible vehicle and to be substantially transparent to the mid-frequency array. Minimal degradation of the mid-frequency received or transmitted signals occurs due to the transparency of the high-frequency array. Benefits of the present invention include providing wide area search capability with the mid frequency array and high-resolution homing and object classification, among other things, with the high-frequency transducer array.

Descriptors :   *HYDROPHONES, *SONAR, *PATENTS, *SUBMERSIBLES, SIGNAL PROCESSING, FREQUENCY, METALS, DENSITY, HIGH FREQUENCY, LAYERS, POLYMERS, ARRAYS, HIGH RESOLUTION, COEFFICIENTS, SIGNALS, ELECTRODES, PIEZOELECTRICITY, PIEZOELECTRIC MATERIALS, TRANSDUCERS, LOSSES, UNDERWATER VEHICLES, DUAL MODE, ACOUSTIC VELOCITY, HOMING, NOSES, RADIOFREQUENCY, ACOUSTIC WINDOWS, AREA SCANNING

Subject Categories : Acoustic Detection and Detectors
      Submarine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE