S11 Calibration Method for a Coaxial-loaded Cut-off Circular Waveguide using SOM Termination

In this study, termination with conditions referred to as short, open and reference material (SOM) was used for S
11
calibration at the front of samples with a coaxial-feed-type cut-off circular waveguide as a preliminary step for dielectric measurement in liquids. With pure water as the reference material, the S
11
value for the jig at the front of the sample was then calibrated in the frequency band of 0.50 to 3.0 GHz using a VNA (vector network analyzer) via the proposed method. Next, S
11
at the front surface of the sample was measured with various liquids in the jig after calibration. The results showed close correspondence of measured values for each method, thereby indicating the validity of the proposed S
11
calibration approach.