A novel antenna beam switching technique on mobile devices for MIMO applications

In this article we will introduce an antenna structure with reconfigurable pattern, which comprising an active antenna and current draggers. We treat the antenna ground as a part of the radiator. Therefore, controlling the Rf current on antenna ground can manipulate the radiation pattern of the antenna. The current dragger, which intrinsically is a kind of pseudo antenna or a low-Q resonator, is installed on the antenna ground. With a controller and switches, we can change the rf current distribution by enabling or disabling the current draggers. It was confirmed that by changing the control current to the switches, the main beam direction of the antenna can be switched in the azimuthal plane. The antenna was fabricated and measured and the results for the return losses show reasonable agreement.