Smartphones are now the biggest piece of the mobile device market, and users want to download more data every year - sending photos, streaming videos and logging on to social networks. But there's a limit to the wireless network, the amount of radio spectrum, any given phone carrier such as Verizon or Sprint can offer its customers.
Disease Detection Goes Mobile
But MIT researchers may have a solution. They built a kind of filter that would allow a radio receiver, like those on a smartphone, for example, to pick out a certain radio frequency easily, while blocking out unwanted noise. That means phones and tablets could use the radio spectrum allotted with less need for "empty" frequencies between channels, as well as hop to signal bands they don't currently use. (This is one reason phones from the U.S. don't work in countries like Japan; the radio in the phone isn't geared to working with the frequency of the local network).
In work to be presented in June at the International Conference on Solid-State Sensors, Actuators and Microsystems, Dana Weinstein, professor of electrical engineering and computer science, and Laura Popa, a graduate student in physics, built a resonator that converts radio signal to vibrations and back to an electrical signal with a gallium nitride transistor.