Multiple characteristic modes excitation for pattern reconfigurable antennas design

The study of the Characteristic Modes (CMs) on a square conductive plane has been addressed to design a pattern reconfigurable antenna. More in detail, it is demonstrated that an efficient stimulation of suitable current modes distribution (J_n) by a proper placing of capacitive exciters over the square plate is able to provide a pattern reconfigurable capability. In particular, the positioning of the capacitive coupling exciters (CCEs) allows stimulating three current modes, whose modal excitation degree can be easily controlled. An appropriate phase shifting between the CCEs enables to control the modal excitation coefficient of the current modes, allowing the pattern reconfigurability.