Circular membrane piezoelectric ultrasonic transducer

Abstract

The invention relates to a circular membrane piezoelectric ultrasonic transducer, which aims to provide a vibration piezoelectric ultrasonic transducer with high transduction efficiency in order to overcome the shortcoming that the conventional ultrasonic transducer is low in transduction efficiency. The circular membrane piezoelectric ultrasonic transducer comprises a siliconchip, a supporting layer positioned on the siliconchip, and two piezoelectric transduction units positioned on the supporting layer, and is structurally characterized in that: the external piezoelectric unit encircles the internal piezoelectric unit; and the two units provides alternating-current excitation of which the constant phase difference is Pi, so the working efficiency of the transducer is improved. The specific sizes of the two units can be optimally regulated according to a design requirement of the transducer.

Description

technical field [0001] The invention relates to a transducer, in particular to a circular thin-film piezoelectric ultrasonic transducer with high conversion efficiency between mechanical energy and acoustic energy. Background technique [0002] Piezoelectric transducers are widely used in electronic devices, household appliances, and mobile phones, such as piezoelectric speakers and piezoelectric receivers, or ultrasonic imaging systems for medical diagnosis and industrial testing. [0003] Generally speaking, a transducer is a device that applies an alternating voltage to a piezoelectric ceramic layer (Piezoelectric Ceramic Layer), thereby causing the layer to alternately expand and contract. For an ultrasonic transducer, although it stretches only a few microns in size, the layup can move up to several centimeters per second because it vibrates hundreds of thousands of times per second. Such as figure 1 As shown in Fig. 2, the traditional piezoelectric transducers lay re...

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Problems solved by technology

However, because the traditional structure uses a single piezoelectric unit, and the excitation given by the piezoelectric unit to the vibrating diaphragm is in the same direction, the excitation direction given to the vibrating diaphragm by the edge of the single piezoelectric unit is the same as that given by the central part of the piezoelectric unit. Opposite to the excitation direction of the vibrating diaphragm

Since the fundamental frequency vibration covers most of the energy of the vibration, the excitation energy given by the piezoelectric unit to the vibrating diaphragm has a significant offset effect, which greatly reduces the working efficiency of the piezoelectric transducer

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