A broadband free-space dielectric measurement system

There are two X-band ripples horn single-lens antennas, waveguide transmission segment, fixture, a mounting station, an Agilent N5225A network analyzer and a computer in the free-space measurement system of 8GHz~40GHz frequency range. S
₁₁
and S
₂₁
of sample measured by network analyzer are used to calculate the dielectric constant. A dual calibration technique of SOLT and GRL is used to eliminate errors due to multiple reflections via the surface of the sample. How the X-band free-space measurement system works at 12.4GHz~40GHz frequency range is introduced and measurement results are reported for some absorbing material.