Effect of Transmission Line on Impedance Matching of Atmospheric-Pressure Radio-Frequency Capacitive Microplasma Discharge

In this paper, it is found that the coaxial transmission line between the matching box and the plasma reactor plays an important role in impedance matching of atmospheric-pressure radio-frequency capacitively coupled microplasma discharge characterized by very low capacitance value. The high output voltage across reactor terminal is generated when the external circuit is operating in resonant state driven by power supply. The experimental results show that coaxial transmission line exhibits capacitive characteristics within the working frequency range and its capacitance increases linearly with the length of the transmission lines; the resonant frequency and voltage across the terminal reactor decrease with the length of coaxial transmission line.