In lab, rice-sized chip generates multiple millimeter-wave frequencies

A grain-of-rice-sized chip at Loughborough University is producing a “rainbow” of organized light frequencies, turning one tiny device into a source of multiple millimeter-wave signals. The research team, which also included experts from the University of Sussex, City University of Hong Kong and QXP Technologies, demonstrated the result with a device smaller than a one-euro coin.

The chip contains a microresonator that keeps feeding light through a loop, allowing precisely spaced frequencies to build up into a microcomb. Earlier work on miniature chips had focused on generating one precise millimeter-wave frequency; this team used a single microcomb to produce several frequencies at once. The researchers reported variable-strength signals with precision and stability, including when the system was disturbed.

That matters because millimeter waves provide far more bandwidth than lower-frequency radio bands and standard microwave frequencies. They could therefore support higher-capacity 6G communications, while the same frequencies may also serve radar, spectroscopy and astronomical instruments. Luke Peters of Loughborough University said the technology could help send and receive more information “faster and in higher resolution.”

So what changes in practice? Not yet a phone, satellite or network component: the complete system remains a tabletop laboratory setup. But the chip gives engineers a compact route to multiple stable signals from one microcomb, and the team plans to take the technology out of the lab while investigating smaller, more energy-efficient versions for satellites and other precision systems.

The researchers describe the potential applications as still some way off. Challenges remain before the technology can enter real-world systems, and no deployment timetable is given. The immediate advance is narrower but concrete: a tiny chip has shown that several carefully controlled millimeter-wave frequencies can be generated together and remain stable outside ideal conditions.