Reconfigurable beam scanning using hexagonal slotted parasitic patch antenna array

In this paper, we propose a pattern reconfigurable microstrip antenna with improved beam scanning range. The antenna is a Yagi-Uda structure with center square shaped driven patch and two hexagonal slotted tunable parasitic patches placed on each side of the driven element. The radiation properties of parasitic patches are changed by varying the capacitance of varactor diodes loaded in hexagonal slot. The proposed antenna works in three possible modes namely, reflector-director, director-reflector and broadside at 2.45 GHz. The simulation result shows that the main beam of antenna radiation can be continuously scanned from 18° to 42° and -18° to -42° in reflector-director and director-reflector mode respectively. For broadside mode, the main beam of antenna is steered to 0°, with a gain of 3.55 dBi. The beam scanning range has been further enhanced, by applying truncated ground plane, achieving a symmetrical beam scanning from -46° to 46°.