A High-Frequency Beamforming Channel for Ultrasound Stimulation and Ultrasonic Powering
H. Rivandi (TU Delft - Bio-Electronics)
Ishaan Ghosh (Student TU Delft)
T. Lopes Marta da Costa (TU Delft - Bio-Electronics)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
New non-imaging ultrasound applications, such as ultrasound stimulation and ultrasonic power transfer, need sub-millimeter volumetric spatial resolution, electronically control of the focal spot location, high ultrasound intensity, and a tiny form factor. Satisfying these requirements demands a high-frequency phased array ultrasound transducer. On the other hand, the pitch size in a phased array must be half of the sound wavelength to avoid grating lobes in the ultrasound beam profile. In other words, higher frequency results in a smaller available area to implement a high-voltage electronics beamforming channel. While prior efforts have reached a maximum frequency of 8.3 MHz, this work utilizes a low area high-voltage level shifter coupled with optimum phase wrapping to present two 15 MHz and 12 MHz pixel-level pitch-matched beamforming channels that deliver 20 V and 36 V to the ultrasound transducer load, respectively. Furthermore, the phase of the output is programmable with 3-bits resolution that allows fine control of focal spot location. The proposed beamforming channels have been implemented in 0.18-µm BCD technology and consume 960 µA and 1.23 mA from 20 V and 36 V power supplies, respectively.