A Simple Tri-Polarization Reconfigurable Magneto-Electric Dipole Antenna

A simple magneto-electric (ME) dipole antenna with reconfigurable polarizations has been designed. The proposed ME dipole antenna mainly comprises three pairs of horizontal rectangular patches, a Γ-shaped feed, a metallic cavity, and four PIN diodes. By independently controlling the on/off state of the PIN diodes, the horizontal rectangular patches can be connected/disconnected, thus exhibiting linear polarization, right-hand circular polarization, and left-hand circular polarization. The experimental results demonstrate that the proposed ME dipole antenna has a wide effective bandwidth of 33.9% from 1.74 to 2.45 GHz for both S11≤ -10 dB and axial ratio ≤3 in all polarization states, and a stable gain of 8.2 ± 0.8 dBi. Good unidirectional radiation characteristic and low backlobe level are achieved over the whole operating frequency band. A prototype was fabricated, and good agreement between measured and simulated results validates polarization diversity of the proposed antenna.