IEC 62783-1-1:2022

Overview

IEC 62783-1-1:2022 - Twinax cables for digital communications - Part 1-1: Time domain test methods - General requirements - specifies time-domain test methods, parameters and requirements for test fixtures used with twinax (twin‑axial / twin‑coaxial) cables and symmetric cables with pitch. The standard defines how to measure differential, common‑mode and single‑ended transmission parameters using time‑domain techniques (TDR/TDT), and sets requirements for test equipment, fixtures, calibration and reporting to support reliable signal integrity assessment at high data rates.

Key topics and technical requirements

• Time‑domain methods: Defines Time Domain Reflectometer (TDR) and Time Domain Transmission (TDT) measurement approaches and how time‑domain displays (voltage/impedance vs time or electrical length) are used to locate and quantify discontinuities.
• Measurement equipment: Preferred setups include a sampling oscilloscope with dual‑channel TDR modules (two 2‑channel modules) or a 4‑port Vector Network Analyser (VNA) with time‑domain capability via IDFT (per IEC 62153‑1‑1).
• Test leads and cables: Use four phase‑stable, low‑loss 50 Ω coaxial leads of equal electrical length (cable length should be as short as possible, typically < 1 m).
• Test fixtures and thru kit: Fixtures must meet frequency‑response requirements across the test bandwidth. Errors from fixtures shall be removed (e.g., de‑embedding or TRL). A Thru kit (same design as fixture with electrical length twice that of a single fixture) is defined for calibration.
• Parameters and definitions: Includes rise time (typically expressed in ps), differential mode characteristic impedance (Ω), single‑ended impedance (Ω), differential and common‑mode propagation delay (ns/m), intra‑pair and inter‑pair skew (ps/m or ns/m).
• Measurement procedures: Covers calibration, de‑skew, establishing reference planes for TDR/TDT measurements, actual measurement steps and test reporting requirements.

Applications and who uses this standard

• Cable manufacturers - design verification, production test and quality control for twinax and symmetric cables.
• Test laboratories & certification bodies - standardized time‑domain measurement procedures for compliance and comparison.
• OEMs, hyperscalers and system integrators - validate cable performance for high‑speed digital links (signal integrity, impedance matching, skew and delay).
• RF/test equipment vendors & R&D teams - develop fixtures, test systems and de‑embedding techniques aligned with the IEC requirements.

Related standards

• IEC 62783‑1 (Twinax cables - Generic specification)
• IEC 62153‑1‑1 (IDFT/time‑domain description referenced for VNA time‑domain analysis)
• IEC 60050‑726 (Electropedia terms for transmission lines and waveguides)

Keywords: IEC 62783‑1‑1:2022, twinax cables, time domain test methods, TDR, TDT, differential impedance, propagation delay, skew, test fixtures, VNA, signal integrity.