The very first magnet-free, non-reciprocal circulator on a silicon chip was recently unveiled, operating at millimeter-wave (mm-wave) frequencies (near or above 30 GHz). This breakthrough was presented by Colombia Engineering researchers at the IEEE International Solid-State Circuits Conference.

Electronic devices mainly fall into the reciprocal category, meaning the signals travel the same way when moving forwards and reverse. Circulators are of the non-reciprocal variety. In these devices, signals traveling in different directions can take alternative paths and be separated.

In the past, non-reciprocal devices have been plagued with bulky designs and high prices, making them inconvenient for consumer wireless electronics. The Colombia Engineering team developed a new way to allow non-reciprocal transmission. The design’s foundation relies on the careful synchronization of high-speed transistor switches.

“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,” according to Colombia Engineering.

With this new design approach, circulators can sustain mm-wave capabilities while using conventional semiconductor chips. This enables two-way wireless or full-duplex communications, which opens up new bandwidth resources.

“This gives us a lot more real estate," says Harish Krishnaswamy, associate professor of electrical engineering at Colombia Engineering. “This mm-wave circulator enables mm-wave wireless full-duplex communications, and this could revolutionize emerging 5G cellular networks, wireless links for virtual reality, and automotive radar.”

Echoing Krishnaswamy's sentiments, autonomous cars are prime examples that would benefit from this research. Onboard radars require full-duplex abilities operating at mm-wave frequencies. The virtual reality (VR) market would also benefit, switching current wired connections to full-duplex, mm-wave wireless links.

“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 full details of the research can be found in a paper recently published in Nature Communications.

To learn more, watch the video below.