Effects of connectors and improper mounting of air lines in TRL calibration

Precision coaxial air transmission lines serve as traceable primary standards in the calibration of vector network analyzers. Measurement errors caused by non-ideal connectors of air transmission line used for ‘Thru-Reflect-Line’ calibration of vector network analyzers are investigated, as well as those caused by improper mounting. The measurement errors are quantified through a comparison between results achieved via TRL and offset-short calibrations. The experimental results demonstrate the susceptibility of the TRL method for transmission lines with imperfect connectors and improper mounting. The resulting measurement errors are of systematic nature and few orders of magnitude larger than the repeatability of the measurement.