Improvement Of Near-field Radiation Characteristics Of The Circular Plane Piston Transducer

The Plane Piston Transducer has been widely used in Ultrasonic detection and other Ultrasonic application technologies for a long time. Because this transducer not only has a firm structure and uses the longitudinal Mechanic-Electricity coupling coefficient of piezoelectric crystals, but also can be easily made, it has very good electricity-sound ability. But the sound field generated by this kind of transducers in medium has s ome "congenital" shortcomings: There always exist zero areas in sound-axes of near-field however we change the frequencies and radii of transducers, so we need to look for better radiate transducers.In this dissertation, we design and make two kinds of radiate transducers: Bunchiness Control transducer with Electric polarity division and Gaussian transducer. We not only discuss their radiate sound fields and the structure characteristics, but also measure the sound press value in sound-axes and radial direction in experiments, we prove that these two kinds of transducers can effectively eliminate the zero areas in near-field, and even more, Gaussian transducer decreases the sound undulation in near-field. Their shortcomings and deficiencies are also illustrated. We hope to make more thorough research in the future.