EPFL scientists have developed a single antenna that is capable of transmitting the same data as a two-antenna (or more) system, allowing for future lower-cost, more compact, energy-saving mobile devices.

Currently, MIMO (multiple-input, multiple outputs), used in devices such as wireless modems, uses several antennas to transmit and receive signals. It poses problems because it is costly and difficult to integrate into hardware.

In a MIMO system, antennas generally have to be placed at a certain distance from each other, which makes inserting them into cell phones and miniature devices a complicated process, and each separate transmitting antenna must have its own encoding and amplifying signal device, which is costly and energy-consuming.

The EPFL technique, called “Beamspace MIMO,” allows for significantly reducing the number of physical antennas, and only one coding and amplifying device is required

Ref.: O. N. Alrabadi, J. Perruisseau-Carrier, and A. Kalis, MIMO Transmission using a Single RF Source: Theory and Antenna Design, IEEE Trans. Microw. Theory Tech. and IEEE Trans. Antennas Propag. Joint Special Issue on MIMO Technology, 2012, DOI: 10.1109/TAP.2011.2173429

Ref.: O. N. Alrabadi, J. Perruisseau-Carrier, and A. Kalis, MIMO Transmission using a Single RF Source: Theory and Antenna Design, [PDF] (open access)