Abstract:

When using surface wave plasma column in stealth plasma antennas, it is difficult to improve conductivity of the surface wave plasma column for low-frequency excitation. This paper studies the relationship between conductivity and the excitation power/frequency of the monopole surface wave excitation weakly ionized plasma
column. This is done by analyzing the equilibrium relationship between the plasma density and power. A  scheme for stabilizing the excitation power and frequency is proposed, using the direct digital frequency synthesis and power gain automatic control techniques to improve the plasma column conductivity. Experiments are carried out to study relationship between the physical properties of the plasma column conductivity and the plasma column density and length. Compared with the original excitation system without using the proposed method, this scheme can improve plasma column conductivity and the overall performance of the system.

Key words: surface wave plasma column, conductivity, excitation system, direct digital frequency synthesis, power gain automatic control