A pattern-reconfigurable water-loaded MIMO antenna

A novel radiation pattern reconfigurable multiple-input multiple-output (MIMO) antenna based on the loading of water is presented. By altering the situation of loading and unloading the distilled water on the surface of the parasitic element, the function of the parasitic element can be switched between a director and a reflector. According to the Yagi-Uda principle, the antenna creates a directional radiation pattern in the azimuth plane through the electromagnetically coupled parasitic elements. A good direction is achieved with the front-to-back of 13 dBi. The MIMO antenna consists of 2 identical elements lying orthogonally to each other. As a result, high-isolation (>35 dB) and low-envelop correlation coefficient ((e)<0.0001) between MIMO elements are obtained by orthogonal dual-polarization antenna element. Good agreement is achieved between the measured results and the simulated results.