High-frequency and power-efficiency ultrasound beam-forming processor for handheld applications

In this work, we develop a high-frequency and power-efficiency ultrasound beam-forming processor which consists of two 8-channel Low-Voltage Differential Signaling (LVDS) receivers and a 16-channel beam-forming module. The proposed LVDS receiver includes the front-end receiving buffer of a pre-amplifier, a hysteresis comparator and an adjustable delay chain, and the back-end signal extractor of a de-serializer. Here, the telescopic pre-amplifier and hysteresis comparator are designed to have high gain-bandwidth products to fulfill highspeed operations. The de-serializer adopts a double triggering technique to expedite serial-to-parallel data conversion. Particularly, the self-adaptive mechanism is developed to automatically adjust a phase delay of each channel. The beam-forming module performs delay and sum operations of input signals from all channels. The proposed 16-channel beam-forming processor implemented by TSMC 0.18μm 1P6M CMOS technology has a die size of 5.0mm×6.0mm, and consumes fairly low power. Additionally, it can support 30MHz ultrasound images via LVDS transmissions at a bit rate of 2Gbps. Therefore, the beam-forming processor proposed herein can be widely applied to various handheld ultrasound systems.