Ant-Sized IoT Radio


Our new paper on Wireless Power Delivery to mm-sized IoT nodes is out!


For over a hundred years and starting from Marconi’s experiment, several generations of wireless devices have connected people with stations and with each other, resulting in over 6 billion mobile subscribers in the world today. The next exponential growth in connectivity is no longer in access between people but in connecting objects and machines in the age of “Internet of Things (IoT)”. Projections show sensor demand growing from billions in 2012 to trillions within the next decade and this is largely fueled by emergence of smart sensors that combine computation, communication, and sensing.  Ultra-low power smart radios that can provide unique IP addresses and their locations are the requirement for IoT.

In this context, battery-less radios are the ultimate frontier in scaling the size and cost of a communication node. They face unique challenges in addressing the need for sufficient data rate without using a power supply. However, there are several key challenges that still need to be addressed in this area. Cost (dominated by antenna board and interface), number of readable transponders (and latency in doing so), data-rate capacity, localization and miniaturization are the issues faced by today’s designers.  Addressing these challenges will open up new application areas for IoT. This could be in commercial, medical or industrial scenarios.

In the first phase of the project we have demonstrated a single-chip 24GHz/60GHz passive radio implemented in 65nm CMOS. This chip is fully self-sufficient with no pads or any external components (e.g. power supply). It integrates RX and TX antennas and provides a communication range up to 50 cm. A modified M-PPM 60GHz transmitter (6-bits per slot) is used to communicate data sequence as well as the local timing reference. Pulse signaling enables real-time localization through time-of-flight. The chip operates with a standby recovered power of less than 1.5uW coming from the reader.

Stanford News

Youtube Video

Technical Article:

M. Tabesh, M. Rangwala, A. M. Niknejad, A. Arbabian, “A Power-Harvesting Pad-Less mm-Sized 24/60GHz Passive Radio with On-Chip Antennas,” VLSI Circuits (VLSIC), 2014 Symposium on. IEEE, 2014.

For more information please contact:

arbabian AT stanford DOT edu