IEC 61726:2022

Overview

IEC 61726:2022 is the latest international standard established by the International Electrotechnical Commission (IEC) for measuring the screening attenuation of cable assemblies, cables, connectors, and passive microwave components. The standard specifies the use of the reverberation chamber method-also known as the mode stirred chamber method-to quantitatively assess how effectively these components block or attenuate electromagnetic interference signals.

This fourth edition replaces the 2015 version and incorporates significant updates such as expanded scope definitions, enhanced measurement principles, and detailed procedures for accurate and repeatable screening attenuation assessment. IEC 61726:2022 is essential for manufacturers, test laboratories, and quality assurance professionals engaged in evaluating electromagnetic compatibility and signal integrity of high-frequency components.

Key Topics

• Screening Attenuation Measurement Principle
  The standard introduces a clear methodology based on the reverberation chamber method, which involves placing the Device Under Test (DUT) inside a mode-stirred chamber to create statistically uniform electromagnetic fields. This setup enables precise attenuation measurement across a broad frequency range.

• Applicable Components
  The standard covers a wide range of items including:

  • Cable assemblies
  • Cables
  • Connectors
  • Passive microwave components such as waveguides, phase shifters, diplexers, multiplexers, power dividers, and combiners

• Measurement Equipment and Setup
  IEC 61726:2022 details the required instrumentation and test setups, including:

  • Frequency synthesizers and spectrum analyzers for signal generation and analysis
  • The reverberation chamber and mode stirrers for creating uniform field distributions
  • Input and reference antennas designed for accurate coupling
  • Stepper motors, linking devices, and sampling systems to automate and optimize data collection
    Emphasis is given on equipment calibration, return loss, and dynamic range to ensure measurement accuracy.

• Device Under Test (DUT) Preparation and Installation
  Guidelines are provided for properly preparing and mounting cables, connectors, and other passive components, minimizing measurement variability and errors.

• Measurement Procedures
  The document outlines step-by-step protocols including frequency sweep configurations, sampling positions, and data normalization to calculate screening attenuation accurately.

• Caution and Safety Notes
  Important considerations such as controlling mode stirrer speed, managing lossy devices, avoiding oscillations and resonances, and safely handling high power levels are addressed to ensure reliable results and operator safety.

• Acceptance Criteria and Reporting
  IEC 61726:2022 defines acceptance criteria that help determine compliance with screening requirements and specifies detailed reporting requirements for documentation and traceability.

Applications

The reverberation chamber method outlined in IEC 61726:2022 is highly valuable in various practical scenarios, including:

• Electromagnetic Compatibility (EMC) Testing
  Assessing screening effectiveness of components that must meet strict EMC regulations in automotive, aerospace, telecommunications, and defense sectors.

• Quality Assurance and Product Development
  Ensuring cable assemblies and microwave components deliver consistent performance with verified attenuation levels before mass production or deployment.

• Troubleshooting and Failure Analysis
  Identifying shielding weaknesses or defects in passive components to prevent signal degradation or interference in high-frequency systems.

• Research and Standardization
  Supporting manufacturers and laboratories in developing new cable and connector designs that require validated test methods for screening attenuation.

Related Standards

IEC 61726:2022 refers to and complements several important standards for electromagnetic and microwave testing:

• IEC 62153 Series
  Provides test methods for screening attenuation at lower frequencies and standard-shaped components. IEC 61726 extends measurement capabilities to higher frequencies and complex shapes through the reverberation chamber method.

• ISO/IEC Directives
  Ensures that the document complies with internationally recognized processes for standard development, facilitating global harmonization.

• Electropedia and IEC Vocabulary (IEV)
  For consistent terminology and definitions in electromagnetic compatibility and electrotechnology.

By adhering to IEC 61726:2022, industries benefit from standardized, reproducible, and reliable screening attenuation measurements, improving component performance and compliance with international electromagnetic compatibility requirements.