Enhancement of Radiation Efficiency of Plasma Antenna in Reconfigurable Central Plasma Antenna Array

This paper discusses different methods to improve the radiation efficiency of plasma antennas in the Reconfigurable Central Plasma Antenna Array (RCPAA). The simulation is carried out in CST Microwave Studio, which shows that optimising the orientation and size of the gap introduced between the ground plane and surface wave coupler (SWC), representing a novel application of the defected ground plane (DGP) technique to plasma antennas, improves the gain and radiation efficiency. This paper proposes a modified equivalent circuit model incorporating additional lumped elements ( and ) to analyse the coupling effect on the plasma antenna. The RCPAA achieves an of −32.72 dB at 850 MHz with a improved gain of 3.3 dB and impedance bandwidth of 500 MHz. The gap also contributes to more than a 10% increase in the radiation efficiency of plasma antennas at resonant frequency, with a maximum efficiency of 25%.