Capacitive ultrasonic transducer with net backplate

A study is presented of the function of an air-coupled capacitive ultrasoni c transducer with uniform net backplate. Net backplates are an easy, fast-t o-assemble alternative to grooved backplates. The frequency responses of th e transducers were measured and the resonance frequencies were estimated. A procedure to study the electrostatics of the transducer with net backplate geometry is described with calculations of surface charge density distribu tion, capacitance and sensitivity.