Precision Automated Reflectometer Using Air-Line Spans UHF through Millimeter Ranges References

The precision swept frequency reflectometer uses a precisely dimensioned coaxial air-line or waveguide of suitable length for the frequency resolution required as an in situ impedance reference. The unknown impedance at the far end of the above reference creates a rotating unknown reflection phasor at the near or measuring device end of the line during swept frequency measurement. A waveguide reflection measurement is described by Hollway and Somlo and the coaxial arrangement by Lacy and Oldfield.