A Study of Plasma Applications in Microwave Circuits
Abstract:
An investigation into the potential usefulness of plasmas in microwave structures, with or with out a static magnetic field, was made. Attention was concentrated on two plasma-microwave configurations. The RF properties of a coaxial transmission line with a slotted outer conductor which passed through a cylindrical glow dis charge were examined. The permittivity of the gas in the line within the discharge chamber could be varied by applying a voltage between the inner and outer conductors, since this determined the extent to which the plasma was drawn into the RF propagation region. The transmission charac teristics were examined for a plasma column length of 30.5 cm for frequencies between 500 to 4200 Mc. Argon, helium and nitrogen gas were used at pressures between 0.02 mm Hg and 2 mm Hg. The results are compared with theory using a Lorent zian model to describe the electron motion in the RF field.