ADJUSTABLE ANTENNA USING PLASMA MEDIUM

Abstract

Plasma antenna is a type of radio antenna in which plasma is used instead of the metal elements of a traditional antenna. One of the advantages of using plasma antenna is it can improve conventional devices in terms of switching (on/off) the antenna using plasma generator, which could make it invisible to the radar. In addition, when antenna conductivity can be controlled through manipulation of plasma parameters, an adjustable antenna can be designed. The aims of this research are to design and simulate plasma antenna using CST software, and subsequently determine the characteristics of plasma antenna with different neon pressure applied (10, 15, 20 Torr). The custom-made cylindrical discharge tube shape with the length and diameter of 160 mm and 10 mm was used. The research focuses on simulation in obtaining antenna parameters while conducting an experimental work to obtain electrical parameters which are needed in calculating the plasma parameters. The discharge tube shape was designed and simulated using Computer Simulation Technology (CST) that can generate antenna parameters such as return loss, gain, directivity and radiation pattern. The simulation result shows the radiation pattern of discharge tube as omni-directional and it gives neon discharge at 20 Torr that has the best performance in return loss at -24.490250 dB, compared to neon at 15 and 10 Torr which have lower values at -21.578 dB and -13.901 dB respectively. In terms of gain and directivity, neon at 10 Torr has the highest value, which is 2.688 dB and 5.437 dBi, respectively. From the results, it can be concluded that when gas pressure is increased, the antenna gains decreases. Neon discharge at a middle pressure of 15 Torr is considered to provide a good antenna gain and give effective signal transmission compared to lower pressure of 15 and higher pressure of 20 Torr.