ELF/VLF radiation resistance of an arbitrary oriented finite dipole in a cold, uniform multicomponent magnetoplasma

2014 By using a full electromagnetic-wave theory, an analysis is made of the ELF/VLF radiation resistance of a finite electric dipole, oriented at arbitrary angle in a cold, uniform magnetoplasma. The general integral expression for the radiation resistance R is derived, and from that, various approximate closed forms of R are obtained for the entire VLF/ELF range. Numerical plots of R are given for the plasma parameters appropriate to the regions of topside ionosphere and magnetosphere. It is found that, in the frequency range in which the refractive index surface of the nmode has an open branch, the radiation resistance R reaches a maximum value whenever the dipole is so oriented that its axis of symmetry is perpendicular to the plane containing the edge of the nmode resonance cone. This relative maximum Rmax is ~ ~h/r0 (h, r0 being the half-length and radius of the dipole, respectively). In the ELF range, this Rmax is shown to occur for the dipole orientation closely parallel to the magnetic field for the high-density plasma considered. For a fixed dipole length and a fixed normalized plasma frequency (f0/fHe), it is shown that R in the ELF range can be comparable to that in the VLF range. LE JOURNAL DE PHYSIQUE TOME 32, NOVEMBRE-DÉCEMBRE 1971, Classification Physics Abstracts 05.10, 14.20