IEC 62153-4-16:2016

Overview

IEC 62153-4-16:2016 is part of the IEC 62153 series on metallic communication cable test methods. It defines a validated method to extend the frequency range of triaxial EMC measurements: extrapolating measured transfer impedance to higher frequencies and screening attenuation to lower frequencies when using the triaxial set-up (per IEC 62153-4-3 method B and IEC 62153-4-4). The procedure is intended for homogeneous screens (screen transfer impedance proportional to length) and accounts for the triaxial frequency behaviour through coupling equations and dielectric properties.

Key topics and requirements

• Scope and purpose
  • Extension of frequency coverage for triaxial measurements: higher frequencies for transfer impedance, lower frequencies for screening attenuation.
• Applicability
  • Applicable to homogeneous screens (transfer impedance ∝ length). The screen’s transfer impedance may follow any frequency behaviour (not necessarily +20 dB/decade).
• Triaxial set-up parameters
  • Uses the triaxial measurement geometry described in IEC 62153-4-3 and IEC 62153-4-4 (method B).
  • Typical coupling lengths: transfer impedance measured with max ~0.5 m (upper limit ≈ 100 MHz); screening attenuation measured with 2–3 m coupling length (upper limit for transfer impedance ≈ 10 MHz, lower limit for screening attenuation ≈ 100 MHz).
• Analytical basis
  • Frequency behaviour derived from coupling equations (see IEC TS 62153-4-1) and depends on coupling length, relative dielectric permittivity of inner/outer circuits and impedance/load ratios.
  • Some derivations neglect capacitive through-screen coupling and attenuation; the standard explains how to include test-head effects and extract electrical length.
• Measurement prerequisites
  • DUT (cable under test) matched at near/far ends for the presented equations.
  • Determination of relative dielectric permittivity and test-head influence is required for reliable extrapolation.

Practical applications

• Cable manufacturers: extend EMC characterization beyond direct measurement bands for product development and quality control.
• Independent test labs and certification bodies: extrapolate triaxial test data to demonstrate compliance across wider frequency ranges without additional complex setups.
• EMC engineers and system designers: assess shielding performance (transfer impedance and screening attenuation) over frequency ranges relevant to real-world installations.
• R&D teams: compare braid/foil designs and predict shielding performance where direct measurement is impractical.

Related standards

• IEC 62153-4-3 - Surface transfer impedance, triaxial method (method B)
• IEC 62153-4-4 - Screening attenuation test method (triaxial)
• IEC TS 62153-4-1 - Introduction to electromagnetic screening measurements
• IEC 61196-1 and IEC TR 62152 - background on cable specifications and two-port transmission properties

Keywords: IEC 62153-4-16, transfer impedance, screening attenuation, triaxial set-up, EMC, metallic communication cable test methods, homogeneous screen, dielectric permittivity.