Researchers are first to demonstrate a circulator on a silicon chip at mm-wave frequencies that enables nonreciprocal transmission of waves: device could enable two-way radios and transform 5g networks, self-driving cars, and virtual reality.
Columbia Engineering researchers, led by Harish Krishnaswamy, associate professor of electrical engineering, in collaboration with Professor Andrea Alu’s group from UT-Austin, continue to break new ground in developing magnet-free non-reciprocal components in modern semiconductor processes. At the IEEE International Solid-State Circuits Conference in February, Krishnaswamy’s group unveiled a new device: the first magnet-free non-reciprocal circulator on a silicon chip that operates at millimeter-wave frequencies (frequencies near and above 30GHz). Following up on this work, in a paper published today in Nature Communications, the team demonstrated the physical principles behind the new device.
Most devices are reciprocal: signals travel in the same manner in forward and reverse directions. Nonreciprocal devices, such as circulators, on the other hand, allow forward and reverse signals to traverse different paths and therefore be separated. Traditionally, nonreciprocal devices have been built from special magnetic materials that make them bulky, expensive, and not suitable for consumer wireless electronics.
The team has developed a new way to enable nonreciprocal transmission of waves: using carefully synchronized high-speed transistor switches that route forward and reverse waves differently. In effect, it is similar to two trains approaching each other at super-high speeds that are detoured at the last moment so that they do not collide.
The key advance of this new approach is that it enables circulators to be built in conventional semiconductor chips and operate at millimeter-wave frequencies, enabling full-duplex or two-way wireless. Virtually all electronic devices currently operate in half-duplex mode at lower radio-frequencies (below 6GHz), and consequently, we are rapidly running out of bandwidth. Full-duplex communications, in which a transmitter and a receiver of a transceiver operate simultaneously on the same frequency channel, enables doubling of data capacity within existing bandwidth. Going to the higher mm-wave frequencies, 30GHz and above, opens up new bandwidth that is not currently in use.
“This gives us a lot more real estate,” notes Krishnaswamy, whose Columbia High-Speed and Mm-wave IC (CoSMIC) Lab has been working on silicon radio chips for full-duplex communications for several years. His method enables loss-free, compact, and extremely broadband non-reciprocal behavior, theoretically from DC to daylight, that can be used to build a wide range of non-reciprocal components such as isolators, gyrators, and circulators.
“This mm-wave circulator enables mm-wave wireless full-duplex communications,” Krishnaswamy adds, “and this could revolutionize emerging 5G cellular networks, wireless links for virtual reality, and automotive radar.”
The implications are enormous. Self-driving cars, for instance, require low-cost fully-integrated millimeter-wave radars. These radars inherently need to be full-duplex, and would work alongside ultra-sound and camera-based sensors in self-driving cars because they can work in all weather conditions and during both night and day. The Columbia Engineering circulator could also be used to build millimeter-wave full-duplex wireless links for VR headsets, which currently rely on a wired connection or tether to the computing device.
“For a smooth wireless VR experience, a huge amount of data has to be sent back and forth between the computer and the headset requiring low-latency bi-directional communication,” says Krishnaswamy. “A mm-wave full-duplex transceiver enabled by our CMOS circulator could be a promising solution as it has the potential to deliver high speed data with low latency, in a small size with low cost.”
The Latest on: Wireless full-duplex communications
- New Scheme for Efficient Use of Drones in 5G Networkson June 22, 2020 at 8:27 am
Researchers from Tomsk Polytechnic University (TPU) collaborated with researchers at Qatar University and Texas A&M University at Qatar to develop a framework for transferring data and energy to ...
- Siklu mmWave Wireless Helps Protect Lady Libertyon June 20, 2020 at 5:00 pm
wireless solutions provided by Siklu Communications. Siklu offers a variety of field-proven mmWave products with a wide range of capacities (1Gbps to 10Gbps Full Duplex) and supported distances.
- Full Duplex Radio Claimed Easier With Analog Moduleon June 19, 2020 at 5:00 pm
IEEE Spectrum recently had a post claiming the company is releasing the K6 module that can be “easily installed in most any wireless system.” RF can seem like black magic, but we can envision ...
- Indicator Gives Local, Remote Position of Load Tap Changeron June 17, 2020 at 5:00 pm
The Model 1250B provides highly accurate, local & remote indication of load tap changer position and other difficult synchro-based position readings, now with improved communications options. Nov 06, ...
- SCALA RIDER joins the GEICO MOTORCYCLE HOT BIKE TOUR 2014on June 16, 2020 at 5:00 pm
SCALA RIDER by Cardo Systems Inc., Joins the GEICO MOTORCYCLE HOT BIKE TOUR 2014. SCALA RIDER will be displaying their market leading wireless ... intercom communication with your passenger, or up to ...
- Power/Performance Bits: June 16on June 16, 2020 at 12:11 am
In fact, extra energy and elements are needed to amplify and relay the signal again and again, which introduces noise, lowers signal-to-noise ratio, and, ultimately, reduces communication bandwidth,” ...
- A Field Guide To The North American Communications Toweron June 13, 2020 at 5:00 pm
The need for clear and reliable communication has driven technology ... turns phones into walkie-talkies that can operate in full-duplex mode. This is great for disaster recovery situations ...
- Ajit Pai caves to SpaceX but is still skeptical of Musk’s latency claimson June 10, 2020 at 10:05 am
The Federal Communications Commission has reversed course on whether to let SpaceX and other satellite providers apply for rural-broadband funding as low-latency providers. But Chairman Ajit Pai said ...
- IIT Kanpur invites online applications for 5G course taught via MATLAB Projectson June 8, 2020 at 9:52 pm
His research area included Multimedia Wireless Communications ... mmWave MIMO, FBMC, NOMA, Full Duplex and others. He has contributed to the 802.11n high throughput wireless LAN standard This ...
- One-Way Electronic Devices Double the Data Capacity of Wireless Networkson June 4, 2020 at 7:27 pm
Image used courtesy of Columbia University Non-Reciprocal Devices To Redefine 5G and Quantum Computing Defying the principles of reciprocity will allow the development of high-power transmitters for ...
via Google News and Bing News