Height Reduction of Circular and Linearly Polarized Magneto-electric Dipole Antenna through Artificial Magnetic Conductor

This article presents a solution for reducing the height of magneto-electric dipole antennas by using an artificial magnetic conductor structure as the antenna's ground plane. Two types of antennas were investigated: a linearly polarized antenna and a right-handed circularly polarized antenna. For the linearly polarized antenna, a 7 x 7 array of artificial magnetic conductor cells (AMCs) was designed at 3.5 GHz and placed on the antenna's ground plane. By adding artificial magnetic conductors, the height of the first antenna was reduced to 0.16 λ. The simulation results show that the impedance bandwidth for values of |S11|<[-10dB] is 1.9 GHz from 2.3 GHz to 4.2 GHz (58.46%), while the measured impedance bandwidth of fabricated prototype is 2.13 GHz from 2.21 GHz to 4.34 GHz (65.03%). The second antenna, which is a right-handed circularly polarized magneto-electric dipole antenna fed by a Y-shaped feed line, has also been improved using an artificial magnetic conductor structure on its ground plane. A 5 x 5 array of AMC cells is used to reduce the height of the antenna to 0.13 λ. The simulation results show an impedance bandwidth of 1.24 GHz from 2.46 GHz to 3.7 GHz (40.25%), while the fabricated prototype has an impedance bandwidth of 1.3 GHz from 2.38 GHz to 3.68 GHz (44.52%).