IEC 62153-4-6:2017

Overview - IEC 62153-4-6:2017 (Surface transfer impedance, Line injection method)

IEC 62153-4-6:2017 is an international test method for evaluating the screening effectiveness of shielded metallic communication cables by measuring surface transfer impedance using the line injection method. The standard specifies a controlled procedure for applying a defined current/voltage to the cable screen (outer circuit) and measuring the induced longitudinal voltage in the conductor(s) (inner circuit). Measurements can be made from a few kHz up to and above 1 GHz using common high‑frequency instrumentation. (Edition 2.0, 2017‑08)

Key technical topics and requirements

• Purpose: Determine the transfer impedance ZT (and equivalent ZTE when capacitive coupling is non‑negligible) per unit length to quantify shielding performance.
• Test principle: Injection circuit constructed as a transmission line (parallel wires, corrugated ribbon or flat braid) placed tightly along the cable under test (CUT); injection feature provides coaxial-to-line transition.
• Frequency range: From a few kHz to >1 GHz with standard RF instrumentation.
• Equipment:
  • Vector Network Analyser (preferred) or signal generator + receiver (with amplifiers/attenuators as needed).
  • Time Domain Reflectometer (TDR) with <350 ps rise time (or VNA return‑loss transformed to time domain).
• Impedance matching: Injection circuit characteristic impedance must match the generator output and load; reflection coefficient of injection feature and injection circuit shall be <0.1 (return loss >20 dB).
• Measurements & evaluation:
  • Calibration procedures and measuring setups (near‑end / far‑end) are specified.
  • Consideration of capacitive coupling (through capacitance C or admittance YC) and temperature correction.
  • Results expressed as transfer impedance, normalized screening attenuation and reported in a standardized test report.
• Measurement precautions: Guidance on reduced primary current, uncontrolled currents, and screen inhomogeneities.

Practical applications and who uses this standard

• Cable manufacturers and designers use IEC 62153-4-6 to:
  • Validate and optimize screen designs (braids, foils, drains) for EMC.
  • Compare shielding performance across product variants.
• EMC test laboratories and certification bodies use it for compliance testing and performance verification.
• System integrators, telecom equipment manufacturers, procurement/specification engineers and R&D teams use transfer impedance data to assess cable suitability in EMC‑sensitive installations (industrial control, telecom, automotive wiring, data centers).
• Useful for troubleshooting EMI issues, specifying procurement limits, and documenting screening performance in technical datasheets.

Related standards

• Other parts of the IEC 62153 series (Metallic communication cable test methods), including IEC 62153‑4‑1 for background on transfer impedance concepts and related measurement techniques.