A wideband antenna with switchable beams

This paper proposes a low profile wideband pattern reconfigurable stacked patch antenna, which is composed of four antenna elements. Each antenna element has two switchable feeding ports. Individual excitation at the two feeding ports can produce a 180° phase-shifting due to the symmetrical structure. A reconfigurable 2×2 prototype is developed by employing four single-pole double-throw (SPDT) switches. By properly selecting the feeding ports for the four antenna element, the 2×2 antenna array can generate four beams including sum beams, difference beams in XOZ and YOZ planes and bi-difference beam. The measured 10-dB impedance bandwidths are 5.18–6.01 GHz, 5.17–6.24 GHz, 5.17–6.23 GHz and 5.18–6.24 GHz for the sum, x-difference, y-difference and bi-difference beams, respectively.