IEC 62153-4-11:2009

Overview

IEC 62153-4-11:2009 specifies a standardized test method to determine coupling attenuation and screening attenuation of patch cords, coaxial cable assemblies and pre-connectorized cables used in analogue and digital communication systems. Known as the absorbing clamp method, this part of the IEC 62153 series defines equipment, calibration, test-head and extension-cable requirements, measurement set-ups (near‑end and far‑end), and result expression for EMC evaluation of metallic communication cables. This publication is intended to be read in conjunction with IEC 62153-4-5:2006.

Key Topics and Requirements

• Scope: Measurement of coupling/screening attenuation for patch cords, coaxial assemblies and pre-connectorized cables using an absorbing clamp.
• Absorbing clamp method: Uses a ferrite absorber clamp to sample surface currents and convert them to a measurable signal (includes current transformer and measuring receiver).
• Test heads & extension cables:
  • Use unscreened/screened/unbalanced test heads and extension cables matching the cable type under test.
  • Extension cables must match the nominal characteristic impedance and velocity of propagation of the patch cord.
  • Operational attenuation of the near-end termination (including test heads) should be < 1 dB up to 100 MHz.
• Balun requirements (30 MHz – 1 GHz):
  • Primary impedance typically 50 Ω (unbalanced); secondary matched to 100 Ω or 150 Ω for balanced outputs.
  • Operational attenuation ≤ 10 dB; return loss ≥ 6 dB.
  • Output signal balance: ≥ 50 dB (30–100 MHz) and ≥ 30 dB (100 MHz–1 GHz).
• Impedance matching: Required only when return loss is < 10 dB; expected mismatch error ≤ ±0.5 dB.
• Test samples: Minimum single‑ended patch cord length is 1 m; double‑ended cords may be measured at any length (special cases for >6 m).
• Measurement sensitivity: Set-up sensitivity must be at least 6 dB better than the specified acceptance limit for the device under test.
• Calibration & validation: Detailed calibration and verification procedures are defined to ensure repeatable EMC results.

Applications and Users

This standard is essential for:

• Manufacturers of patch cords, coaxial assemblies and pre-connectorized cables validating EMC performance
• Independent test laboratories performing compliance and quality control testing
• EMC engineers, telecom installers and system integrators verifying screening/coupling performance in analogue and digital communications
• Product development teams ensuring designs meet screening attenuation targets

Keywords: IEC 62153-4-11, absorbing clamp method, coupling attenuation, screening attenuation, EMC testing, patch cords, coaxial cable assemblies, test heads, balun requirements.

Related Standards

• IEC 62153-4-5:2006 (absorbing clamp method - general)
• IEC 61196-1 (coaxial communication cables – generic specification)
• IEC 60050-726 (terminology for transmission lines)
• ITU‑T G.117 and O.9 (measurement/ unbalance guidance)