Antenna pattern distortion by an isotropic plasma slab

Abstract

in the direction of sheath motion) of the reflected wave and of the wave in the moving medium are first found. From the longitudinal components all other field components are determined for an arbitrary orientation of the plane of incidence and an arbitrary angle of incidence. Several special cases are solved completely for both an incident E-wave and an incident H-wave. It is found that the results are particularly simple when the moving sheath is a uniaxial magnetoplasma. REFERENCE[l] C. T. Tai, "Electrodynamics of moving anisotropic media: The fist-order theory,"[5] S . W. Lee and Y. T. Lo, "Reflection and transmission of electromagnetic waves by a moving uniaxially anisotropic medium," J. , "On waves in an anisotropic plasma imbedded in a moving dielectric medium," , "On guided waves in moving anisotropic media," IEEE Trans. Microwave Theory and Techniques, vol. MTT-16, pp. 99-103, February 1968.[8] -, "Wave behavior at an interface of a semi-infinite moving anisotropic medium,"Abslract-A quantitative laboratory experimental investigation has been conducted on the distortion of the main far-field radiation pattern of a horn antenna situated behind a layer of isotropic plasma. The power radiation pattern and phase for orthogonal components of the radiation transmitted through the plasma were investigated for various plasma properties.The experimental results were compared to theory based on the reciprocity theorem and good agreement was obtained. The major features are a gradual attenuation and distortion of the radiation pattern for plasma electron densities below the critical density and a rapid change in the radiation pattern with severe attenuation in the region of the critical electron density followed by "cut-off"at still larger electron densities. No appreciable polarization change of the energy radiated by the antenna is introduced by the plasma.