An aperture coupled patch antenna system with MEMS-based reconfigurable polarization

An aperture coupled patch antenna suitable for IEEE 802.11b/g WLAN applications is described. The antenna system enables the polarization of the device to be dynamically reconfigured, where the reconfiguration is actuated by an RF microelectromechanical system (MEMS) single-pole double-throw (SPDT) switch. An equivalent circuit model of the RF MEMS switch is used in the electromagnetic simulations of the antenna. This enables an accurate analysis of the antenna cross-polarization, which is highly dependent on the switch isolation. Theoretical results are given for the return loss, radiation patterns and gain of the antenna in both vertical and horizontal polarization states.