Multiple frequency steerable acoustic transducer

A multiple frequency acoustic transducer comprising:

• a stacked configuration of N groups of multi-layer transducer elements separated from one another by an electrical insulating material, each of said multi-layer transducer elements from an n-th one of said N groups having a layer of acoustically transparent electro-acoustic transducer material of selected thickness t.sub.n determined as a function of the speed of sound C.sub.LAYER in said layer of acoustically transparent electro-acoustic transducer material of selected thickness t.sub.n and a desired frequency of operation f.sub.n ;
• each of said multi-layer transducer elements from an n-th one of said N groups having opposing planar surfaces with electrically conductive material deposited thereon;
• said electrically conductive material on at least one of said opposing planar surfaces for each of said multi-layer transducer elements being formed into parallel strips electrically isolated from one another;
• and
• said parallel strips associated with each of said multi-layer transducer elements in said n-th one of said N groups having a unique angular orientation in said n-th one of said N groups.