Researchers at the University of Waterloo are working on an inexpensive and low-power wireless system to connect electronics in the home using the 60-gigahertz (GHz) band. The technology would allow someone to send high-definition photos or video clips from a BlackBerry or other phone directly to a high-definition television or display. It would also dramatically decrease the time it takes to send or receive these huge data files.
“No mobile device, currently, can do it. In new applications using the 60-GHz band, your high-definition screen can become a remote display for your BlackBerry,” says Dr. Safieddin Safavi-Naeini, the NSERC-RIM Senior Industrial Research Chair in Intelligent Integrated Radio/Antenna Systems and Novel Electromagnetic Media Technologies.
Dr. Safavi-Naeini has many projects underway at the Center for Intelligent Antenna and Radio Systems (CIARS), which he directs at Waterloo. This particular project is part of a research program focused on extremely high-frequency waves known as the millimeter-wave band. The 60-GHz band is one of several high-frequency bands, each with the potential for different consumer, commercial, scientific and medical applications. It can carry almost 30 times more data than the frequency bands that are mostly used today. But signals at the 60-GHz frequency are prone to atmospheric attenuation, cannot travel long distances, and are blocked by solid objects, including the human body.
This means there are several obstacles involved in developing an inexpensive, wireless 60-GHz system that would work in the home, particularly in regard to mobile links which need rapid adjustment of the radiation beam. Multiple antennae are required and they would have to be able to focus specifically on the source of the 60-GHz signal, rather than on a broad reception area.
A system with multiple antennae needs a way to combine all the signals into one output. Phase shifters would work, but can be expensive. Transmitted power is quite small in the millimeter wave band, so low-noise amplifiers are essential in order to differentiate signal from noise. The multiple antennae require multiple low-noise amplifiers, which use a lot of energy.
To address the problems, the University of Waterloo group is developing relatively inexpensive silicon-based integrated passive lenses, which are similar to optical lenses but can direct electromagnetic waves.
The team used CMOS technology and developed a new topology that provides adequate noise performance but, importantly, consumes much less power than existing solutions, says Mehrdad Fahimnia, a PhD student working on the project.
For example, the researchers were able to integrate multiple low-noise amplifiers on a small area of the chip along with the lens. This achieves reduced power consumption and can improve performance and battery life. It will be the first fabricated Si-based millimetre wave integrated active Rotman lens at 60GHz, says Fahimnia.
CMC Microsystems helped the researchers by providing access to design tools, materials, and test equipment that contributed to their efforts. The work is funded by Research in Motion, which has patented the new technology in the USA and Europe and is doing the same in Canada, says Fahimnia.
“We want to implement the technology at an economical level so it can be commercialized and open new market opportunities for emerging millimeter wave communications systems.”