Pattern Reconfigurable Dual-Polarized Dipole Antenna With Staggered Parasitic Elements

This paper presents a pattern reconfigurable dual-polarized dipole antenna with staggered parasitic elements operating in 3.5 GHz band. The proposed antenna is designed by assembling two linearly polarized antennas to be orthogonally polarized, and each antenna includes two parasitic elements and a single dipole element. A circuit including a varactor is inserted into each parasitic element, and the current phase of the parasitic element changes according to the capacitance of the varactor. Each antenna has a beam steering range of about ±30° in the E-plane, and the beamwidth and gain are maintained uniformly regardless of the steering angle due to the angled parasitic element. Also, because of the continuously changing characteristic of the varactor, the beam of the proposed antenna is steered continuously, and only four varactors are used. The size of the fabricated dual-polarized antenna is
$1.40\lambda _{0}\times 1.40\lambda _{0}\times 0.47\lambda _{0}$
, and the measured results confirm that the antenna has an average gain of around 6 dB with 0.3 dB gain variation.