MULTIRESONANCE ULTRASONIC TRANSDUCER BASED ON MEMS FOR SUPER DIRECTIVITY ULTRASONIC DISTANCE MEASUREMENT USING PARAMETERIC TRANSMITTING ARRAY IN AIR AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a pMUT type ultrasonic transducer manufacturable to integrate an ultrasonic actuator part and an ultrasonic sensor parts together by an MEMS.;SOLUTION: The ultrasonic transducer, which can be used for measuring a distance to a target by using ultrasonic waves in the air, comprises the ultrasonic actuator part and the ultrasonic sensor part. The ultrasonic actuator part is formed by regularly and alternately arranging two types of resonance unit actuators, which are an f₁ resonance unit actuator and an f₂ resonance unit actuator individually having resonance frequencies at two ultrasonic frequencies f₁ and f₂ for generating two ultrasonic waves at high voltage in the air and forming a parametric transmitting array in the air to generate a high-directivity difference tone (f_d=f₁-f₂) wave. The ultrasonic sensor part is constructed of at least one or more unit sensors having a resonance frequency at the frequency (f_d=f₁-f₂) of the difference tone for sensing an ultrasonic signal reflected on the target and returned.;COPYRIGHT: (C)2008,JPO&INPIT