Plasma travelling wave antenna
The possibility of using plasma column as linear travelling wave antenna is studied. It is shown that surface current waves propagating in plasma column of finite length are a source of paraxial electromagnetic radiation of decimeter band. Influence of dielectric waveguide, which surrounds cold isotropic plasma, on dispersion properties of plasma column is investigated. The corresponding dispersion equation for eigenwaves of circular dielectric waveguide filled with plasma is derived and solved numerically. Plasma and waveguide parameters are determined under which the surface wave slowing-down is close to unity leading to antenna’s radiation primarily in axial direction. It is shown that in case of plasma density around 1012–1013 cm–3 dispersion of the considered wave is close to dispersion of waves propagating in metal travelling wave antenna.
G. G. Borg, J. H. Harris, N. M. Martin, D. Thorncraft, “Plasmas as antennas: Theory, experiment and applications,” Phys. Plasmas 7, No. 5, 2198 (2000).
Ye. N. Istomin, D. М. Karfidov, I. М. Minayev, and А. А. Ruhadze, “Plasma non-symmetrical vibrator with surface wave induction,” Fizika Plazmy 32, No. 5, 423 (2006).
K. Walter, Travelling Wave Antennas (Energiya, Moscow, 1970) [in Russian].
N. A. Krall and A. W. Trivelpiece, Principles of Plasma Physics (McGraw-Hill, New York, 1973; Mir, Moscow, 1975).