Shielding Model of Single-Braided RF Cable Considering Structural Characteristics of Triaxial Method

Radiofrequency (RF) cables are widely used in the automotive, aerospace, and defense industries as cable assemblies. Several electromagnetic compatibility (EMC) tests have shown that the issue of radiated emissions (RE) primarily affects interconnected power cables and cable connectors. Consequently, measuring transfer impedance, a parameter that indicates the effectiveness of cable shielding, has become increasingly important. The triaxial method for measuring transfer impedance is defined by the European Committee for Electrotechnical Standardization (CENELEC) under EN 50289 and by the International Electrotechnical Commission (IEC) under IEC 62153. However, discrepancies have been noted between the transfer impedance results measured using the triaxial method and the theoretical calculations. Therefore, this paper presents the termination conditions, setup, and equivalent circuit of the triaxial method. Further, the measurements are compared with theoretical calculations by using an RF RG402 single-braided cable. Moreover, an error analysis reveals that a modified theoretical formula, which considers the structural characteristics of the triaxial method, better conforms with the measurements.