Estimation of Measurement Uncertainties in TEM-Cells based on Generalized Telegraphist's Equation

This work examines the uncertainties of electric field measurements in coaxial TEMcells with a circular cross-section. The TEM-cell can be used as a standardized field generator for probe calibration or EMC measurements. The main advantage of a coaxial TEM-cell with a circular cross-section is the inherent transverse cross-section, an enlarged frequency bandwidth, and the possibility of efficiently calculating its electromagnetic characteristics. Based on the generalized telegraphists equations, the electromagnetic fields and the TEM-cells resonance frequencies can be calculated. Using this approach, we can include various uncertainty factors into our mathematical model equation. We will derive all necessary equations for a complete uncertainty evaluation of a coaxial TEM-cell following the GUM.