Engineers at the College of Engineering Wireless Communications Lab have been awarded $400,000 from the National Science Foundation to test electrically-small biomimetic antenna arrays inspired by one of the most sensitive auditory systems in the animal world - the ear system of an insect. In collaboration with the University of Wisconsin-Madison, they will research cutting-edge methods to increase the data rate in wireless communication systems equipped with multiple antennas (MIMO) which will at the same time reduce the size and power consumption of a mobile device.
"The potential payoff of this research is significant," explains Dr. Hamid Bahrami, the lead principal investigator of the project. "The technology that we currently develop in our lab enables very small mobile devices to provide communication speeds not easily matched by the current technologies. The main obstacle to further developing this technology involves signaling techniques suitable for the devices to exploit their full potential, and this grant will fund research to those solutions."
The Wireless Communications Lab has an extensive background in multiple antenna systems. "This is an emerging technology in research areas of wireless communications: to find ways to make the distance between antenna elements smaller while having the same or better performance," asserts Ardalan Alizadeh, a graduate student on the project. "Consequently, the application of this technology is not only limited to cellular mobile phone services." Their findings could go a long way in managing the challenges of limited bandwidth.
In fact, a potential application of this project is in the design of cognitive radio networks -- a new paradigm where smart devices are able to utilize spectrum bands in an efficient way. This feature is considered to be a key enabling technology for the next generation of wireless standards, which is why their research received the NSF's "Enhancing Access to the Radio Spectrum (EARS)" award.
The parasitoid fly Ormia Ochracea has become a model organism in acoustical experiments because of its unique "ears," which are complex structures inside the fly's chest near the bases of their front legs. The fly is too small for the time difference of sound arriving at the two ears to be calculated in the usual way, yet it can determine the direction of sound sources with exquisite precision. Using designs that mimic this sensitive biological system, the proposed methods by the lab aim to reduce the inter-antenna spacing of mobile devices without degrading the performance, making it possible to implement antenna arrays with multiple elements in mobile devices.
As technology stands now, the current generation of mobile devices such as your 4G smartphone is usually equipped with two or four antennas. While a multiple antenna design increases the communication speed and can potentially reduce power consumption of mobile devices, it occupies large real estate that in turn increases the size of your phone. Since the distance between elements in typical antenna arrays is currently in the range of a few inches depending on the frequency band, the size of a radio like your smartphone with more than four antennas would become quite large, and that hinders mobility. The lab's solution aims to reduce the spacing between MIMO antennas inside the smartphone, keeping it small and portable.