Skip to main content

New Filter Design Uses Graphene

A bulletin from Columbia University's Fu Foundation School of Engineering and Applied Science, Using Graphene to Make Wireless Communications More Flexible, caught my attention, as the technology described could resolve many of the issues raised in the FCC Future of Wireless Band Plans Forum (see my article covering the Forum) by providing very small, low powered, easily tunable RF filters. 

Michael Lekas and Sunwoo Lee, electrical engineering Ph.D. candidates, have developed a way to use a small sheet of graphene as a tunable resonator in a filter. Similar to the quartz crystal or ceramic resonator in a conventional filter, the graphene sheet vibrates at its resonant frequency. To make this graphene filter even more interesting, the electrical characteristics of the graphene change, which tend to amplify the desired signal, while blocking noise and interference.

The device can be electrically tuned by as much as 400 percent. 

“Plus it’s much smaller and, therefore, easier to integrate onto a conventional silicon chip, compared to the existing filter technologies,” Lekas said. “This device could substantially improve the flexibility, miniaturization, and integration of wireless transceivers, which would make devices such as cell phones smaller, faster, and more energy efficient.”

The research earned the Columbia team a Qualcomm Innovation Fellowship award and the accompanying $100,000 prize.

The team will be mentored by Victor Abramsky, VP of Engineering at Qualcomm's New Jersey Research facility. He commented, “Qualcomm views Graphene resonators, pioneered by the Columbia team, as an important element in next generation wireless technology,”

I'll be watching to see how this technology develops. Lekas and Lee plan to design, fabricate, and test graphene electromechanical filters with their Qualcomm Fellowship. If a practical filter can be built using this technology at low cost, it will have application in almost every area of RF communications.