Nanowatt wake-up receivers: exploring power and sensitivity trade-offs

Many emerging applications in wearable sensors, unattended ground sensor networks, and other Internet-of-Things (IoT) devices measure signals such as human physiochemistry, ambient temperature, or the presence of intruders - all of which are signals that do not tend to vary rapidly with time. In such systems, battery life is often dominated by radios - not because of large payloads, but rather due to the constant communication of small packets in order to maintain network synchronization. This presentation will discuss how wake-up receivers (WuRXs), if designed for bandwidths that support the average expected throughput needs of a given application, can be used to dramatically reduce average power consumption in such applications. Conventional wake-up radio architectures will be reviewed and analyzed for their strengths and weaknesses, followed by detailed discussions on state-of-the-art architecture and circuit techniques that can be used to improve sensitivity and/or reduce WuRX power consumption.