EN IEC 61788-15:2026

Overview

EN IEC 61788-15:2026 is an international standard developed by the International Electrotechnical Commission (IEC) and adopted as a European Standard by CENELEC (CLC). This document specifies procedures for accurately measuring the intrinsic surface impedance (Zs) of high-temperature superconductor (HTS) films at microwave frequencies. Using a modified two-resonance mode dielectric resonator method, this standard addresses the temperature dependence of the intrinsic surface impedance at the resonant frequency, enabling precision characterization essential for both research and industrial applications.

This second edition of the standard supersedes the 2011 edition, introducing significant technical improvements to increase measurement reliability and comparability across laboratories and use cases. The standard is critical for those developing and applying superconducting films in electronic and microwave applications, offering standardized methodologies for consistent results.

Key Topics

• Measurement Range

  • Frequency: Up to 40 GHz
  • Applicable film thickness: Greater than 50 nm
  • Measurement resolution: 0.01 mΩ at 10 GHz

• Intrinsic Surface Impedance (Zs = Rs + jXs)

  • Surface resistance (Rs) and reactance (Xs) are measured as functions of temperature, which are fundamental characteristics in superconducting electronics.

• Standardized Procedure

  • Utilizes a dielectric resonator with two resonance modes and components including a vector network analyzer, cryogenic system, and specialized mounting hardware.
  • Key measurement variables include resonance frequency, quality factor (Q-value), and temperature stability.

• Data Reporting

  • Results are to be listed at the measured frequency and scaled to 10 GHz using frequency dependence rules (f² for Rs, f for Xs) to enable cross-comparison.

• Technical Updates in 2026 Edition

  • Addition of an informative Annex on combined relative standard uncertainty in surface impedance measurements.
  • Terminology has shifted from “precision and accuracy” to “uncertainty”.
  • Incorporation of round robin test results to enhance reproducibility and harmonization among laboratories.

Applications

EN IEC 61788-15:2026 is central to the development and quality assurance of superconducting devices for advanced microwave systems. Practical application areas include:

• HTS-Based Microwave Components:

  • Filters, resonators, antennas, and delay lines utilizing superconducting films benefit from extremely low surface resistance and stable surface reactance, enabling efficient, compact, and high-performance devices.

• Materials Development:

  • Accurate measurement of Zs guides the development, optimization, and comparison of new HTS materials and coatings for improved device performance.

• Industrial Quality Control:

  • Standardized impedance measurements provide manufacturers with a basis for quality assurance and specification compliance for superconducting film production.

• Research and Academia:

  • Fundamental studies in superconductivity, especially on temperature-dependent electronic properties, rely on standardized measurements for published data to be reproducible and comparable internationally.

Related Standards

To provide a comprehensive approach to superconductivity measurement and ensure compatibility across different tests and devices, users should consult:

• IEC 60050-815: International Electrotechnical Vocabulary – Superconductivity
• IEC 61788-7: Superconductivity – Electronic characteristic measurements – Surface resistance of high-temperature superconductors at microwave frequencies
• Previous Edition - IEC 61788-15:2011: For reference and comparison of methodology evolution

Conclusion

EN IEC 61788-15:2026 delivers essential guidance for the precise, reliable, and harmonized measurement of intrinsic surface impedance in superconducting films at microwave frequencies. Its adoption facilitates technological advancement in superconducting electronics, strengthens quality assurance processes, and supports consistent research methodologies globally.

For organizations involved in superconductivity, HTS device manufacturing, materials research, and high-frequency electronic design, adherence to EN IEC 61788-15:2026 ensures that performance data are accurate, meaningful, and internationally recognized.