Reconfigurable plasma circularly polarized magneto-electric dipole antenna

This paper proposes a plasma based circularly polarized (CP) magneto-electric (ME) dipole antenna with reconfigurable radiation characteristic. The antenna consists of two horizontal trapezoidal plasma patches, two vertical plasma patches, and shaped metallic cavity. The antenna is fed using Γ-shaped plasma dipole. The antenna introduces wide impedance matching bandwidth of 75 % (from 1.64 GHz to 3.7 GHz) and wide circular polarization bandwidth of 68% (from 1.9 GHz to 3.7 GHz). The operating frequency bandwidth of the ME-dipole is controlled by the plasma frequency according to its applications such as DCS/UMTS (1.71-2.18 GHz), 3G/LTE (1.84-2.69 GHz), and through-the-wall imaging radars (1.6-3.7 GHz). The radiation characteristics of the proposed ME-dipole antenna are investigated for different plasma frequencies. The antenna introduces a stable gain with peak value of 10.7 dB and high efficiency of 95%. A 2×2 ME-dipole antenna array with sequential feed is employed to improve the antenna gain and circular polarized bandwidth of the plasma ME-dipole antenna. Two array arrangements have been investigated for high gain and wideband CP characteristics.