ELECTRET TRANSDUCER WITH VARIABLE ELECTRET FOIL THICKNESS

摘要

ELECTRET TRANSDUCER WITH VARIABLE ELECTRET FOIL THICKNESS An acoustic transducer for producing highly directional characteristics comprises a metalized backplate facing the flat surface of an electrostatically charged electret foil. The thickness of the electret foil varies along the length thereof according to a predetermined relationship. The sensitivity of the electret transducer varies directly with the thickness of the electret foil.