Compact slitted planar monopoles for MIMO systems

Multiple input multiple output (MIMO) systems are a very up-to-date solution to face the growing capacity demand for new wireless communication systems. Generally, MIMO systems employ multiple antennas at both ends of a wireless link. The problem is that the volume occupied by multiple antennas is often prohibited, especially for modern compact handsets. Recent studies have shown that multiple antennas can be replaced by a single multimode antenna, like the archimedian spiral proposed. A different approach to reduce the size of the system consists in using compact integrated diversity antennas. This antenna, which is based on a Y-patch, incorporates two antennas into one, and uses two isolated feed ports to provide diversity signals. The objective of this paper is to present two monopole designs valid for MIMO applications that are based on the operating principle proposed. Measurements for the designs have been carried out at Technical University of Cartagena, with the aim of verifying the suitability of the antennas for MIMO systems.