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On the Theory of Radiation From an Annular Slot in a Compressible Plasma
Author(s) -
Yeh Y. S.,
Wait James R.
Publication year - 1968
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1002/rds196832171
Subject(s) - physics , aperture (computer memory) , plasma , flange , waveguide , slot antenna , optics , excited state , boundary value problem , antenna (radio) , materials science , radiation pattern , acoustics , atomic physics , quantum mechanics , electrical engineering , engineering , composite material
Radiation from a circular‐slot antenna in a warm plasma is treated as a boundary‐value problem. The slot is excited symmetrically by a coaxial waveguide which has an infinite flange. The waveguide aperture and the flange are separated from the plasma by a dielectric coating. An exact formulation is given for the fields produced in the plasma region in terms of the aperture field at the open end of the waveguide. An asymptotic evaluation of the integrals shows that, in addition to space wave radiation, a surface wave is excited by virtue of the finite temperature of the plasma. Also, waveguide‐type modes in the dielectric layer are excited and they are attenuated even in the absence of ohmic or collision losses. Finally, a variational formula is obtained for the terminal admittance of the coaxial line.