Compact Reconfigurable Antenna Array for Adaptive MIMO Systems

Reconfigurable antenna arrays increase the flexibility of adaptive multiple-input-multiple-output (MIMO) systems by their reconfigurable configurations and radiation/polarization properties. In this letter, a compact reconfigurable antenna array operating in the UMTS band is proposed. The antenna array consists of two hybrid-monopole-and-dipole elements. Each element, by controlling states of three p-i-n diodes, has two modes: monopole mode and dipole mode. Therefore, the proposed antenna array has four modes. Based on the measured results, these four modes represent four different radiation patterns, which can achieve pattern reconfigurability to increase channel capacity in varying channel conditions.