One-Port Measurements of non-coaxial DUTs with Vector Network Analyzer

In the set ups for EMC testing there is manifold of passive one-port DUTs with non-coaxial terminal (Coupling Decoupling Networks, Artificial Main Networks, Asymmetrical Artificial Networks, etc.). They are verified in the radio frequency range with Vector Network Analyzers VNAs, which unfortunately have coaxial ports. Such DUTs can be connected to the VNA only with insertion of adapters in-between. The adapter shades the DUT. In this paper the method of the DUT's revealment is presented. This approach is preceded with the Short-Open-Thru-Match SOTM calibration. Frequency limitations in applicability of the method is discussed. Validation of the method consists in determination of impedance of the CDN available on the market.