Mobile Computing

UCLA Researchers Build Two-Way Communication Device Using One Frequency

• By Joshua Bolkan
• 10/28/14

Researchers at the University of California, Los Angeles' (UCLA) Henry Samueli School of Engineering and Applied Science have developed a device that can broadcast and receive signals simultaneously on the same frequency with no loss of quality or communication speed. The distributedly modulated capacitor (DMC), as the device has been dubbed, is also able to function on a wide band of the radio spectrum.

The device has potential applications in wireless technologies such as smartphones and "could also lead to the adoption of cognitive radio technologies — a hot topic of study for the wireless industry — which are devices that detect available parts of the spectrum and use them accordingly," according to a UCLA news release.

"Think of incoming and outgoing communication like traffic on a single-level bridge with six lanes — two lanes coming in, two lanes going out, with an additional two lanes in the middle for protection purposes," said Yuanxun Ethan Wang, associate professor of electrical engineering at UCLA and the principal investigator on the research, in a prepared statement. "What our new circulator does is akin to making it a double-deck bridge. Not only that, the separation space between the incoming and outgoing lanes is no longer needed. So now, we can send and receive the same amount of information using the width of just two lanes, or one-third of the original bandwidth used."

While previous devices capable of same-frequency communications used bulky magnetic materials, the DMC uses silicon or compound semiconductor and shifts incoming transmissions to another frequency to be processed while leaving the outgoing signal unchanged.

"For incoming transmissions on the same frequency, the incoming wave is altered into another frequency by small physical movements made by the DMC," according to a UCLA news release. "The outgoing waves stay the same."

"This DMC could bring significant changes to traditional wireless system architectures," Wang added. "It can be incorporated into current integrated circuit manufacturing processes, rather than made as a separate component. This makes it possible to improve integrated circuits without increasing manufacturing costs for communications devices."

More information is available in the published research at ieeexplore.ieee.org.