title: Scattering Parameters Representing Imperfections in Precision Coaxial Air Lines.
abstract: Scattering parameter expressions are developed for the principal mode of a coaxial air line. The model allows for skin-effect loss and dimensional variations in the inner and outer conductors. Small deviations from conductor circular cross sections are conformally mapped by the Bergman kernel technique. Numerical results are illustrated for a 7 mm air line. An error analysis reveals that the accuracy of the scattering parameters is limited primarily by the conductor radii measurement precision.
authors.affiliation: National Institute of Standards and Technology, Boulder, CO 80303.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Holt
keywords: Bergman kernel; coaxial air line; conformal mapping; coupling; cubic splines; error sources; measurement contour; measurement precision; principal mode; scattering parameters; skin effect; surface roughness; telegraphist equations