Receiver design for CMUT-based super-resolution ultrasound imaging

Applications of the capacitive-micromachined ultrasonic transducers (CMUTs) operating in their fundamental frequency of vibration have been extensively studied. Recent research on asymmetric mode of vibration has shown promising results in construction of super resolution ultrasound images. This paper presents the design of a receiver circuit that supports both the fundamental and asymmetric modes of operation. The receiver includes transimpedance amplifiers that convert the current signals from the CMUT devices into voltage. Furthermore, low-power variable-gain stages are included to amplify the resulting signals and facilitate interfacing to the ultrasound imaging machine for additional processing and display. The receiver is designed and laid out in a 0.35-μm CMOS process. Post-layout simulations show that each receiver channel has a nominal gain of 110 dBΩ up to 10 MHz while consuming 925 μW from a 3.3 V supply.