An Ultrasound Imaging Front-End System-on-a-Chip with Element-Level Impedance Matching for Acoustic Reflectivity Reduction

This paper presents an ultrasound imaging front-end system-on-a-chip that reduces the acoustic reflectivity of the ultrasound transducer array in a broad bandwidth. It integrates, for the first time, an ultrasound transceiver (HV pulse transmitter and LV analog receiver) and an element-level active capacitive impedance cancellation scheme using an element-level negative impedance converter. The system is designed for low frame rate applications such as intracranial ultrasound (ICUS) and realized in 180-nm HV BCD technology. The ASIC provides high-voltage pulses up to 60 V consuming 3.6 mW and occupying only 2.5 mm(2). The system-on-a-chip is used with a capacitive micromachined ultrasonic transducer (CMUT) array operating in the 2-4 MHz range and its acoustical reflectivity reduction and imaging capabilities have successfully been demonstrated through pulse-echo measurements and acoustic imaging experiments.

Automated summary

This paper introduces an ultrasound imaging front-end system-on-a-chip that reduces the acoustic reflectivity of the ultrasound transducer array in a broad bandwidth. The system integrates an ultrasound transceiver and an active capacitive impedance cancellation scheme for the first time, designed for low frame rate applications. This system-on-a-chip is used with a CMUT array in the 2-4 MHz range and has successfully demonstrated reduced acoustic reflectivity and imaging capabilities through experiments.