Spatially distributed transducer for towed line array applications

Abstract

Transducers based on the variable reluctance concept, employing magnetiza, soft, plastic materials. These materials serve as the isolator between the conductors of a coaxial cable. Such materials exist in considerable variety. The magnetization is azimuthal, such as can be generated by electrical currents flowing through the coaxial cable. Any isolated section of the coaxial cable constitutes a transducer, the conductors at one end of which form the terminals, while those at the other end are connected together to provide a closed electrical circuit. Pressure changes, caused, for example, by acoustic signals, on the outer surface of this transducer produce changes in volume, which in turn induce electrical signals due to changes of the magnetic flux. The conductors of the cable transducer can be in the form of wire braids or metal films, neither of which will significantly change the elastic characteristics of the magnetizable plastic material. Transducers of this type exhibit an electrical source impedance which is essentially equal to the resistance of the conductors. This eliminates the need of impedance changing preamplifiers. The output signals can be, therefore, transmitted directly over long distances by simple wires placed in the interior of the central, hollow, inner conductor.

Dependencies are inferred from the claim text.