Novel chip technology could free bandwidth for autonomous cars

US researchers demonstrate chip-based method for wireless two-way communication


Ever more technologies are depending on data transmission, from 5G telephony to communication of autonomous cars with each other and their surrounding infrastructure, but the airwaves are getting crowded, and the bandwidth available for that communication is becoming scarce.

A team of electronics engineers at Columbia University in New York has now developed a system that, for the first time, can be integrated onto a standard microchip to get around this problem.

The device the team has developed is called a circulator, and it enables signals to travel into and out of the device along different paths. This is known as non-reciprocal action, and previously has only been achievable with bulky devices made from special magnetic materials that are too expensive for consumer electronics.

In February of this year, Harish Krishnaswamy’s group at Columbia demonstrated the first non-magnetic non-reciprocal components on silicon chips, and has now published a paper in Nature Communications demonstrating the principles behind the device.

The device, which can be made using standard semiconductor fabrication techniques and is therefore both compact and low-cost, enables full two-way wireless communication, in which a transmitter and a receiver of a transceiver operate simultaneously on the same frequency channel, enabling doubling of data capacity within existing bandwidth. It will also allow operation at higher frequencies than are currently in use for mm-wave communication, 30GHz and above, rather than the frequencies below 6Ghz that are now rapidly running out of bandwidth. “This mm-wave circulator enables mm-wave wireless full-duplex communications,” Krishnaswamy said, “and this could revolutionise emerging 5G cellular networks, wireless links for virtual reality, and automotive radar.”

The significance of this for autonomous vehicles is that they need mm-wave radar working alongside ultrasound and camera-based sensors so that they can sense their surroundings in all weather conditions, night and day, and these need to receive and send data simultaneously.

For wireless virtual reality, Krishnaswamy explained, “a huge amount of data has to be sent back and forth between the computer and the headset requiring low-latency bi-directional communication.” Currently, VR headsets depend on a wired tether to the computer operating the system, limiting their usefulness.