Microfabricated ultrasonic transducers with bias polarity beam profile control

Abstract

A capacitive microfabricated ultrasonic transducer with control of elevation phase through alternating bias polarity is disclosed. Such control of elevation phase results in simple ultrasonic probes with excellent slice thickness attributes. Furthermore, tight spatial variation of phase results in an effective way to achieve transmit aperture and apodization control. Further still, such capacitive microfabricated ultrasonic transducers can achieve elevation focus without the need of a lossy mechanical lens.

Description

technical field [0001] The present invention relates generally to the field of ultrasonic sensors, and more particularly to elevation beam profile control of capacitive microfabricated ultrasonic sensors. Background technique [0002] An ultrasonic sensor is an electronic device that emits and receives sound waves. Ultrasonic sensors are acoustic sensors that operate at frequencies above 20 KHz, more generally in the 1-20 MHz range. Ultrasonic sensors are used in medical imaging, non-destructive evaluation, and other applications. The most common form of ultrasonic sensor is a piezoelectric sensor. Recently, a different type of ultrasonic sensor, the capacitive microfabricated ultrasonic sensor, was described and fabricated. Such a sensor is described by Haller et al. in US Patent No. 5,619,476, issued April 9, 1997, entitled "Electrostatic Ultrasonic Transducer." The patent describes sensors capable of operating in gaseous environments, such as air-coupled sensors. Lad...

AI Technical Summary

Problems solved by technology

The Savord patent neither teaches nor suggests such control by spatial distribution of bias polarity

Images