Overview
IEC 61196-1-119:2020 - "Coaxial communication cables - Part 1-119: Electrical test methods - RF average power rating" specifies how to determine the RF average power rating (maximum continuous average input power) of coaxial communication cables at specified frequencies and ambient temperatures (reference usually 40 °C). This second edition (2020) revises the 2012 version: the title was clarified, a test method to determine sufficient test duration was added (Annex A), key calculation equations were corrected, and clauses were reorganized.
Key topics and requirements
- Definition of RF average power rating: power that causes conductor temperatures to reach allowable material limits when cable is terminated in its characteristic impedance.
- Two measurement methodologies:
- Method A (RF test): direct RF power application using an RF source, power meter, coupler and load. Temperatures are measured (recommended with a fibre‑optic thermocouple placed near the inner conductor) and input power increased in stages until conductor temperatures stabilize at limits.
- Method B (Low‑frequency AC method): uses 50 Hz or 60 Hz AC to derive thermal constants (Ki, Ko) for insulation and sheath. These frequency‑independent thermal parameters are then combined with RF attenuation data to calculate RF average power rating - useful when high RF power sources are unavailable.
- Test setup and measurement points:
- Use a cable length long enough to avoid end heat‑sinking effects.
- Temperature measurements at the cable center and at ±0.5 m from center; for RF tests measure at current antinode.
- Ensure natural air circulation around the cable.
- Thermal time constant and duration: Annex A provides a method to determine how long tests must run for temperatures to reach steady state.
- Adjustment to reference ambient: measured results are adjusted to a reference ambient temperature (typically 40 °C).
- Required reporting: procedures, equipment, measured temperatures, attenuation data and the calculated RF average power rating must be documented.
Applications and users
This standard is practical for:
- Cable manufacturers specifying or verifying power handling capability of coaxial cables.
- Test laboratories performing cable qualification and type approvals.
- RF system designers, installers and procurement engineers selecting cables for telecom, broadcast, satellite, radar and microwave links.
- Certification bodies and quality assurance teams ensuring cables meet thermal and power ratings.
Keywords: IEC 61196-1-119:2020, coaxial communication cables, RF average power rating, electrical test methods, power handling capability, thermal constants, Method A, Method B.
Related standards
- IEC 61196-1 - Generic specification for coaxial communication cables.
- IEC 61196-1-113 - Electrical test methods - Test for attenuation constant.