Columbia Engineering

Our systems are getting smaller, and they are getting better.

It wasn’t too long ago that researchers from Columbia Engineering created full-duplex radio integrated circuits (ICs) in nanoscale CMOS that allowed transmission and reception in a wireless radio. This system used two antennas—one serving as the transmitter and the other as the receiver.

Today, another breakthrough technology in the field of telecommunications has been unveiled by the team—a similar system that only uses one antenna; which makes the entire system more compact and even more powerful, as it integrates a non-reciprocal circulator and a full-duplex radio on a nanoscale silicon chip.

"This technology could revolutionize the field of telecommunications," says Harish Krishnaswamy, director of the Columbia High-Speed and Mm-wave IC (CoSMIC) Lab.

Krishnaswamy continues by noting the 'first ever' nature of this breakthrough, "our circulator is the first to be put on a silicon chip, and we get literally orders of magnitude better performance than prior work."

And he comments on the significance, saying that "full-duplex communications, where the transmitter and the receiver operate at the same time and at the same frequency, has become a critical research area and now we've shown that WiFi capacity can be doubled on a nanoscale silicon chip with a single antenna. This has enormous implications for devices like smartphones and tablets."

Silicon Radio Chips

The ability to place the circulator on the same chip as the rest radio can help to reduce the size of the system, improve performance, and it can even introduce new functionalities that are ultimately essential to a full duplex receiver.

"What really excites me about this research is that we were able to make a contribution at a theoretically fundamental level...and also demonstrate a practical RF circulator integrated with a full-duplex receiver that exhibited a factor of nearly a billion in echo cancellation, making it the first practical full-duplex receiver chip and which led to the publication in the 2016 IEEE ISSCC," Krishnaswamy says.

The work was published in Nature Communications,

Share This Article