THEORETICAL AND EXPERIMENTAL INVESTIGATIONS OF SURFACE-WAVES PLASMA COLUMN AND MICROWAVE PLASMA SOURCE FOR APPLICATIONS IN RECONFIGURABLE PLASMA ANTENNA

In this paper, we have investigated plasma column excited by surface-waves using monopole plasma antenna. Since the plasma frequency has an important role in conductivity of the plasma column and antenna radiation characteristics, determining the distribution electron density and plasma frequency in the inhomogeneous plasma column axis is particularly important. For this purpose, the plasma column is modelled by fluid equations for high-frequency discharges. Because of significant advantages such as high power handling capability at 2.45 GHz, the surfaguide launcher is chosen from the other conventional launchers to propagate the surface wave along plasma column. The surfaguide is experimentally excited an argon gas-filled tube at a pressure of 0.2 torr as a surface-wave plasma source. In this work, because of safety considerations about high power radiation, plasma frequency measurements was impractical using conventional methods. Therefore, a new system is designed consists of a solid-state VCO, amplifier, circulator, attenuator and two double-ridged horn antennas. The plasma frequency is obtained close to 5.7 GHz, which is consistent with theoretical concepts. (c) 2017 The Authors. Microwave and Optical Technology Letters.