Pseudo-Random Channel Shuffling Time-Division Multiplexing of Ultrasound Echoes in Ultrasound Imaging Integrated Circuits

Next generation wearable/implantable ultrasound imaging systems demand ultra-compact, power-efficient analog front-end circuits enabling high-resolution, high frame-rate multimodal imaging. Individual RF channel access allows for the use of state-of-the-art imaging methods such as synthetic aperture imaging, plane-wave compounding and adaptive beamforming, while remaining crucial for auto-calibration of sparse transducer arrays. Time-division multiplexing-based (TDM) architectures have been widely deployed to enable individual RF channel access, but impose severe trade-offs between power and silicon area for imaging quality and contrast. This work introduces a pseudo-random channel-shuffling TDM (PRCS-TDM) technique, emulating a non-uniform sampling-rate for each RF channel. Results show PRCS-TDM improves B-mode contrast-to-noise ratio (CNR) in anechoic regions up to a 2× increase compared to conventional TDM, achieving a 3.2 dB CNR increase for channel compression ratios greater than 8.