Calibrating a VANA with a slightly lossy beadless coaxial standard line

Abstract

Use of a beadless coaxial standard line to calibrate a vector-indicating automatic network analyser (VANA) provides for measurement of the voltage reflection coefficient Γ in terms of the mode propagated by that line. Owing to skin effects, the impedance Zm assigned to that mode differs from that defined for an ideal lossless line of appropriate dimensions, Zdef (= 50 Ω). The author reports results of expressing the measured Γ in terms of the nominal Zdef for f ≥ 0.05 GHz, after accounting for the conductor loss by measurements with a type N beadless coaxial standard line.