Research out of the University of California, Los Angeles (UCLA) has shown that a single wireless chip – call it the “universal” chip – could be in cell phones, as well as other wireless gadgets, in as few as three years, extending their battery life, allowing for sleeker designs, and permitting them to access features beyond Wi-Fi, GPS, global phone service, and Bluetooth.
Today’s cell phones can contain up to six wireless radio chips, which send and receive information in the form of electromagnetic waves. Each chip has a specific function: there’s one designed to work at the frequency of the cellular carrier’s signal and others for Wi-Fi, GPS, and Bluetooth frequencies.
Historically, engineers have designed these chips to work within only a small range of frequencies in the radio spectrum. For instance, in order to communicate with a cell-phone tower, a chip may be optimized to send and receive information at 900 megahertz (or another frequency depending on the service provider). To access a Wi-Fi signal, a separate chip must be added, to communicate in the 2.4 gigahertz band.
Although some chip makers (such as Texas Instruments) have built and deployed “triband” and “quadband” chips that can tune into three or four different bands, designing a truly universal chip that can access all frequencies has remained a challenge. But the incentive is there: a phone with a universal chip could access any service on the spectrum – from local television and radio, to Wi-Fi and WiMax – in addition to saving power and precious space within shrinking gadgets.
The wireless world doesn’t need more “customized radios that you stuff into a handset,” says Asad Abidi, professor of integrated circuits and systems at UCLA and lead researcher on the universal chip project. Instead, it needs “one versatile radio that is so general and so flexible that [it] can receive TV, Bluetooth connections, and wireless Internet.”
This universal chip would provide flexibility similar to that of a car radio tuner, allowing most stations to be ignored, and zeroing in on just one frequency. The team’s chip design, presented in February at the International Solid-State Circuits Conference in San Francisco, is work that moves toward making a “real tunable radio,” says Bill Krenik, wireless advanced architectures manager at Texas Instruments. Abidi has designed a chip that is capable of accessing all the incoming radio signals, he says, over a spectrum from 800 megahertz to 5 gigahertz.
The UCLA team’s work relies on a technological concept called “software-defined radio,” or SDR. First proposed the early 1990s by Joe Mitola of Mitre Corporation, SDR is based on the concept of converting all incoming radio signals (which are electromagnetic waves and therefore analog) into digital 1s and 0s. This would enable a circuit’s software to sort through different frequency bands, and pick out the one of interest. Using software bypasses the need to design and add a specific radio for each band.