Overview
IEC 61196-1-111:2014 - "Coaxial communication cables – Part 1-111: Electrical test methods – Stability of phase test methods" is an international standard that specifies test methods to determine the stability of phase for coaxial communication cables. This Edition 2.0 (2014) replaces the 2005 edition and introduces revised procedures for phase behaviour under changing environmental and mechanical conditions.
Key topics and technical requirements
The standard defines purpose, equipment, test samples, environment, procedures, results and reporting for each stability test. Major topics include:
- Phase variation with temperature (Clause 4)
- Methods to measure phase change versus temperature and to calculate the temperature coefficient of phase (η_tf) referenced to 25 °C.
- Preconditioning, test environment and plotting phase–frequency/phase–temperature graphs.
- Phase constant variation with temperature (Clause 5)
- Procedures to assess changes to the phase constant and related calculations (phase delay, electrical length).
- Phase stability with bending (Clause 6)
- Mechanical test set-up, bending geometries and measurement of phase change induced by cable bending.
- Phase stability with twisting (Clause 7)
- Twist test procedures and reporting of phase variation due to torsional deformation.
- Definitions and derived metrics in the document include maximum variation of temperature coefficient (Δη_max), ratio of relative temperature coefficient (PT) and total relative variation of phase constant (δβ).
- Test report requirements: specified content to ensure repeatable, traceable results.
Practical applications
This standard is used to verify that coaxial cables maintain predictable phase behavior in real-world conditions. Typical applications:
- Design and qualification of RF and microwave coaxial cables where phase stability affects system performance (e.g., phased arrays, timing-sensitive links).
- Manufacturing quality control and production acceptance testing to ensure batches meet phase-stability specifications.
- Environmental and mechanical validation for installations exposed to temperature cycling, bending, or twisting (outdoor runs, retractable assemblies).
- R&D and materials selection to compare dielectric and construction choices that influence phase stability.
Who should use this standard
- Cable manufacturers and product engineers
- Test laboratories and certification bodies
- RF system designers, installers and integrators
- Quality assurance and compliance teams in telecom, broadcasting, aerospace and defense sectors
Related standards
- IEC 61196-1 - Generic specification for coaxial communication cables (general definitions and requirements).
- IEC 61196-1-108:2011 - Electrical test methods for characteristic impedance, phase, group delay, electrical length and propagation velocity.
This standard is essential for anyone needing standardized, repeatable procedures to assess and report the phase stability of coaxial communication cables under thermal and mechanical stress.
Open preview (PDF)Coaxial communication cables - Part 1-111: Electrical test methods - Stability of phase test methods
