A study of the reference impedance influence on a TRL calibration

In coaxial systems typically beadless air lines are applied as line standards for a high precision TRL calibration of a vector network analyzer. This paper describes the influence of the characteristic impedance of the line standards on the quality of a TRL calibration. The dependency of the air line impedance on the dimensional and material properties is presented and the influence on the measurement results of selected devices under tests is evaluated.