Reconfigurable Plasma Antenna Array for Beamsteering Application at S-band

A beam forming circular Plasma Antenna Array has been designed for VHF and UHF range in CST. In this design a metal antenna which is omnidirectional acts an active element and plasma acts as passive element. Hence, omnidirectional metal antenna is surrounded by a blanket of plasma. The plasma blanket is realized with the use of commercially available fluorescent tubes in which plasma density can be varied with power applied for plasma production. Plasma behaves as a perfect reflector in the region where plasma frequency is greater than operating frequency of the antenna and appears to be transparent for plasma frequency below the operating frequency. A plasma window can be created by turning off or of low plasma density which is transparent to RF. These plasma tubes can be turned off and on in a sequence to provide 360° scanning of the RF signal. Hence, the antenna beam can be directed or steered into any plasma window electrically in all 360° direction which finds its application replacing mechanical steering. The angle of the plasma window can be changed varying the number of tubes used. The result is in terms of radiation pattern, reflection coefficient and VSWR.