Stacked reconfigurable circular patch antenna for adaptive MIMO systems

In this paper we present a novel design of a reconfigurable circular patch antenna (RCPA) for multiple input multiple output (MIMO) communication systems. This antenna allows for high pattern diversity and exhibits good radiation efficiency in all of its configurations. The compact array is capable of dynamically changing the shape of its radiation pattern by selecting a pair of feed points connected to two stacked circular disks. Different electromagnetic modes are excited in the antenna structure to achieve pattern reconfigurability. The performance achievable with this antenna in MIMO systems is determined through channel measurements collected in an indoor environment. Results show a capacity improvement of 11% when using the proposed array at one end of a 2 times 2 MIMO system with respect to a system that employs non reconfigurable antennas.