Impedance measurements and standards for uniconductor waveguide

A tutorial review is presented of the measurement of impedance and reflection coefficient in uniconductor waveguide. Normalized impedance in a waveguide operating in a particular mode is defined and related to measured quantities such as the reflection coefficient and the VSWR. Emphasis is given to the rectangular waveguide operating in its dominant mode and to the tuned reflectometer as an instrument for achieving the most accurate results. The evolution of the tuned reflectometer at NBS is outlined and recent techniques are discussed. Different types of standards of reflection coefficient are described and the advantages and limitations of each are mentioned.