Hydrophone having a directive lobe in the form of a cardioid

摘要

A hydrophone is disclosed which has a cardioid-shaped directional lobe for selective reception of acoustic waves. The device comprises a cylindrical casing having an acoustic window in a rear member thereof and a piezoelectric transducer supported by an annular internally groove front member. A bottom member located in the opening of the front member and spaced from the piezoelectric transducer is provided with a wall element. A ring element is located in the groove of the front member. Cavities are thus formed between the bottom member of the wall element and between the ring element and the front part of the casing to form thin sheets of air for producing acoustic decoupling to permit reception of acoustic waves impinging on the rear member of the casing and minimizing the effect of acoustic waves received from other directions.