A team of professors in the department of electrical and computer engineering at Northeastern University in Boston, MA finally discovered how to make antennas 1,000 times smaller than existing ones.
Until today, we have been able to shrink the size of our computers and smartphones, as well as wearables and implantable electronics so they became faster and cheaper, but the size of the antenna needed for wireless communications has eluded this development. This is the reason that a paper published yesterday (8/29/2017) in Nature Communications, authored by professor Nian Sun and colleagues, is an important step in decreasing the size of electronic gadgets.
"A lot of people have tried hard to reduce the size of antennas. This has been an open challenge for the whole society," Sun said. "We looked into this problem and thought, 'why don't we use a new mechanism?'"
Antenna design is based on the resonance of the electromagnetic wave to be transmitted and received by the antenna. These signals travel almost at the speed of light, so they have a large wavelength. Traditional antenna design requires the physical size of the antenna to be around one-tenth of the wavelength. This makes shrinking the antennas for electromagnetic resonant waves impossible. Hence, the need for a new approach.
The approach taken by Nian Sun and colleagues is based on a paper published three years ago, and available at IEEE Xplore, where a group of researchers suggested the concept of locating magnetic and electric dipole radiators (M- and E-dipoles) to add multifunctionality and switchable characteristics to existing communication systems. These features were needed to refine new applications, including, among others, the anti-collision systems for vehicles prevalent nowadays. The researchers of the Xplore article suggested that a combination of magnetic and electric radiators into an antenna—an ME antenna—may be possible, and if so, it would be an enhancement of antenna arrays.
Based on this idea, the researchers at Northeastern University designed an antenna to receive and transmit at the acoustic resonance frequency of the wave, instead of using its electromagnetic resonance. Acoustic resonance waves are thousands of times smaller than electromagnetic waves, making these new antennas one to two orders of magnitude smaller over the existing ones.
More important, these antennas can be used with our existing small wireless devices such as smartphones and wearables. Also, the advent of the internet of things will take advantage of these tiny devices. Further, antennas of this size will be a welcome improvement to bio-electronic devices that monitor health.
"Something that's millimeters or even micrometers in size would make biomedical implantation much easier to achieve, and the tissue damage would be much less," Sun said.
An abstract of the research results can be found here: https://www.nature.com/articles/s41467-017-00343-8