Design and Experimental Validation of Pattern and Frequency Reconfigurable Central Plasma Antenna Array

The study presents the design and development of a plasma-based antenna array system for the UHF band. The system features an omnidirectional plasma antenna as its active radiator, a novel approach that has not been previously explored. Surrounding plasma reflectors around the plasma antenna form a reconfigurable array. The plasma antenna is the only radiating element in the array, whereas the surrounding plasma reflectors enhance the gain and directivity of the array, facilitating beam shaping and steering. This new design creates a fully plasma based system enabling dual reconfigurability in frequency and radiation pattern. Electronic beam scanning is possible in the azimuthal plane from 0° to 360° in 18° steps. The resonance frequency of the array is optimised to 820 MHz, resulting in a significant increase in plasma antenna gain from −5 to 0 dB within the operating frequency range. Activating the plasma reflectors reduces cross polarisation by 20 dB. The proposed array achieves a 25 dB front-to-back ratio and a bandwidth of 600 MHz. The array's RCS varies from 6 (Formula presented.) to (Formula presented.) (Formula presented.) over the 1–12 GHz range, rendering it invisible from 8 to 12 GHz. This plasma-based array is suitable for radar, defence and navigation systems.