360-degree polarization scanning with the diversity of boresight and conical patterns switching

A novel reconfigurable antenna with the capability of 360-degree polarization scanning and the diversity of boresight and conical radiation patterns switching is presented in this paper. Each shorting-post is connected and controlled by a PIN diode to achieve the desired distribution of electric field null(s) in the substrate, where transverse magnetic (TM) modes switching between TM11 and TM02 can be accordingly realized corresponding to boresight and conical patterns. The antenna is analyzed in a cavity model, which, in terms of electric field, theoretically explains the generation of TM11 and TM02 resonant modes, and provides the audience with an innovative method of designing pattern reconfigurable antennas for the applications such as multiple-input and multiple-output (MIMO), wireless body sensor network (WBSN), Wi-Fi and WiMAX. The proposed antenna is with a competitive radius of 0.32 λg. The antenna structure is very easy to be fabricated. The measurement shows that the antenna can realize a boresight and conical pattern reconfiguration at 2.4 GHz with a gain of 6 dBi and efficiency of 86.7% (boresight mode), and 4.39 dBi and efficiency of 82.4% (conical mode).