Integrated front-end circuit for self-transmitting and self-receiving imaging of air coupling capacitance type micromechanical ultrasonic sensor

Abstract

The invention relates to an integrated front-end circuit for self-transmitting and self-receiving imaging of an air coupling capacitance type micromechanical ultrasonic sensor, which realizes the switching of transmitting / receiving channels through switching signals and realizes the self-transmitting and self-receiving application of the air coupling capacitance type micromechanical ultrasonic sensor. The device comprises a pulse excitation circuit and a transmitting / receiving channel change-over switch, and the output end of the pulse excitation circuit is connected with the first end of the transmitting / receiving channel change-over switch. A second end of the transmitting / receiving channel change-over switch is connected with an alternating-current excitation signal input end and an echo signal output end of the air coupling capacitance type micromechanical ultrasonic sensor through the alternating-current and direct-current coupling circuit, and a third end of the transmitting / receiving channel change-over switch is connected with an input end of the amplifying circuit. On the basis of realizing self-transmitting and self-receiving application of the air-coupled air-coupled capacitance type micro-mechanical ultrasonic sensor, adjustable impedance matching between the receiving end of the front-end circuit and various air-coupled capacitance type micro-mechanical ultrasonic sensors is further realized.

Description

technical field [0001] The invention relates to the technical field of medical and industrial ultrasonic sensing imaging, in particular to a system for self-generating and self-receiving imaging of an air-coupled capacitive micromachined ultrasonic sensor (CMUT). Background technique [0002] In recent years, air-coupled ultrasonic testing technology has played an important role in the medical industry, aerospace, human-computer interaction and other fields with its advantages of non-contact, non-invasive, and completely non-destructive. Compared with piezoelectric ultrasonic transducers, air-coupled capacitive micromachined ultrasonic transducers (Capacitive Micromachined Ultrasonic Transducer, CMUT) have the advantages of large bandwidth, easy acoustic impedance matching with air, easy design of high-density arrays, and easy integration with front-end circuits. , has a good application prospect in the fields of ultrasonic ranging, ultrasonic imaging and gesture recognition...

AI Technical Summary

Problems solved by technology

This has caused great difficulties for the further application of air-coupled capacitive micromachined ultrasonic transducers (CMUTs).

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