prEN 3475-804
(Main)Aerospace series - Cables, electrical, aircraft use - Test methods - Part 804: Velocity of propagation
Aerospace series - Cables, electrical, aircraft use - Test methods - Part 804: Velocity of propagation
This document specifies a method for measuring the velocity of propagation of a cable.
Luft- und Raumfahrt - Elektrischen Leitungen für Luftfahrt Verwendung - Prüfverfahren - Teil 804: Ausbreitungsgeschwindigkeit
Diese Norm legt ein Verfahren zum Messen der Ausbreitungsgeschwindigkeit eines Kabels fest.
Série aérospatiale - Câbles électriques à usage aéronautique - Méthodes d'essais - Partie 804 : Vitesse de propagation
No Scope available
Aeronavtika - Električni kabli za uporabo v letalih - Preskusne metode - 804. del: Hitrost širjenja
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2025
Aeronavtika - Električni kabli za uporabo v letalih - Preskusne metode - 804. del:
Hitrost širjenja
Aerospace series - Cables, electrical, aircraft use - Test methods - Part 804: Velocity of
propagation
Luft- und Raumfahrt - Elektrischen Leitungen für Luftfahrt Verwendung - Prüfverfahren -
Teil 804: Ausbreitungsgeschwindigkeit
Série aérospatiale - Câbles électriques à usage aéronautique - Méthodes d'essais -
Partie 804 : Vitesse de propagation
Ta slovenski standard je istoveten z: prEN 3475-804
ICS:
29.060.20 Kabli Cables
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2025
ICS 49.060 Will supersede EN 3475-804:2002
English Version
Aerospace series - Cables, electrical, aircraft use - Test
methods - Part 804: Velocity of propagation
Série aérospatiale - Câbles électriques à usage Luft- und Raumfahrt - Elektrischen Leitungen für
aéronautique - Méthodes d'essais - Partie 804 : Vitesse Luftfahrt Verwendung - Prüfverfahren - Teil 804:
de propagation Ausbreitungsgeschwindigkeit
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-
STAN.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 3475-804:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Methods . 4
4.1 General. 4
4.2 Frequency domain methods . 4
4.2.1 Method A: coaxial cables — transmission measurement in the frequency domain . 4
4.2.2 Method B: symmetrical cables — balun-based transmission measurement in the
frequency domain . 6
4.2.3 Method C: symmetrical cables — balun-less transmission measurement in the
frequency domain . 7
4.2.4 Method D: symmetrical cables — reflection open/short measurement in the
frequency domain . 9
4.2.5 Expression of test results . 11
4.3 Time domain methods . 14
4.3.1 Method E: coaxial cables — time domain measurement . 14
5 Requirement . 16
Bibliography . 17
European foreword
This document (prEN 3475-804:2025) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, prior to its presentation to CEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 3475-804:2002.
EN 3475-804:2002:
— Frequency domain test methods have been introduced for coaxial and symmetrical cables. They are
based on modern test equipment. Frequency domain test methods are preferred compared to time
domain test methods. Nowadays vector network analysers have the capability to measure the four
S-parameters of a two-port (cable). Those S-parameters are in close relationship to the typical cable
parameters like attenuation, return loss (VSWR) and velocity of propagation. The time domain test
method of the edition 2002 has been updated to clarify the measurement set-up, the measurement
and expression of test results.
1 Scope
This document specifies a method for measuring the velocity of propagation of a cable.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 50289-1-1, Communication cables - Specifications for test methods - Part 1-1: Electrical test methods -
General requirements
EN 50289-1-11:2016, Communication cables - Specifications for test methods - Part 1-11: Electrical test
methods - Characteristic impedance, input impedance, return loss
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Methods
4.1 General
The velocity of propagation may be measured in the frequency or time domain. The measurement in the
frequency domain is the reference method and shall be used if not stated otherwise. The frequency
domain methods are based on EN 50289-1-1, EN 50289-1-7, EN 50289-1-8 and EN 50289-1-11.
Time domain measurement is suitable for a rough evaluation of the velocity of propagation. In case of
doubt the frequency domain methods prevails.
4.2 Frequency domain methods
4.2.1 Method A: coaxial cables — transmission measurement in the frequency domain
4.2.1.1 Test equipment
The test equipment consists of a vector network analyser (VNA) having at least two-ports, and the
following:
— S-parameter set-up (shall be capable of performing S measurements);
— Impedance matching adapters to convert the nominal impedance of the CUT (e.g. 75 Ω) to the
nominal impedance of the VNA (e.g. 50 Ω), in case they are different;
— Calibration standards to perform the required calibration of the test equipment at the test
interfaces. Depending on the nominal impedance of the CUT, the test interface will be at the coaxial
ports of the VNA (or at the end of suitable test cables), or on the secondary side of an impedance
matching adapter. To perform a full two-port calibration at the test interfaces, calibration
standards, i.e. a short circuit, an open circuit, a reference load, and a through connection, are
required. The through connection shall be well matched to the nominal impedance and have a low
attenuation. An alternative to the before mentioned open, short, load, and through references is the
use of an electronic multiport calibration kit (ECal module) which is supplied by the supplier of the
VNA. The calibration standards should be traceable to an international reference standard.
4.2.1.2 Test sample
The cable under test (CUT) shall have a length of at least 10 m, if not stated otherwise. The maximum
sample length shall be such that the attenuation at the highest measured frequency is maximum 80 dB.
Both ends of the CUT shall be prepared, such that when connected to the test ports of the test
equipment the influence on the test result is minimized, e.g. by fitting the CUT with suitable low loss and
well matched connectors.
4.2.1.3 Calibration procedure
It is not the intent of the standard to detail the algorithms applied by a VNA to correct the measured
results based on a calibration procedure, but to detail the calibration procedure. Further information
may be obtained in the manuals of the VNA supplier.
The calibration shall be performed at the test interfaces. A full two-port calibration is recommended,
using calibration standards as described in 4.2.1.1.
If the nominal impedance of the CUT is equal to the nominal impedance of the VNA, the calibration shall
be performed at the coaxial ports of the VNA or at the end of suitable test cables, applying consecutively
the specified open, short, load, and through standards. If the nominal impedance of the CUT is different
from the nominal impedance of the CUT, the calibration shall be performed on the secondary side of the
impedance matching adapters.
4.2.1.4 Measuring procedure
The CUT shall be connected to the test ports of the test equipment, including proper termination of the
screen.
The forward transmission scattering parameter S (complex value) shall be measured over the whole
specified frequency range and at the same frequency points as for the calibration procedure.
The phase angle of the forward transmission scattering parameter S is used for the further evaluation
of the velocity of propagation, see 4.2.5. The phase angle is obtained from the measured forward
scattering parameter by:
Im S
( )
b= arctan (1)
Re S
( )
where:
b is phase in radians
Im(S ) is the imaginary part of the forward transmission scattering parameter
Re(S ) is the real part of the forward transmission scattering parameter
This phase shall be positioned into the right quadrant of a circle. The Excel function ATAN2 does this
transformation.
4.2.2 Method B: symmetrical cables — balun-based transmission measurement in the frequency
domain
4.2.2.1 Test equipment
The test equipment consists of a vector network analyser (VNA) having at least two-ports, and the
following:
— S-parameter set-up (shall be capable of performing measurements);
— Baluns to convert the unbalanced signal of the VNA to a balanced signal. The baluns shall have an
impedance on the primary (unbalanced) side equal to the nominal impedance of the measuring
devices (in general 50 Ω) and on the secondary (balanced) side equal to the nominal impedance of
the cable under test (CUT) (e.g. 100 Ω). The baluns shall fulfil the requirements of Class A baluns as
described in EN 50289-1-1;
— Calibration artefacts to perform the required calibration of the test equipment on the secondary
side of the baluns. To perform a full two-port calibration a short circuit, an open circuit, a reference
load, and a short connection cable or similar, are required. The short circuit shall have negligible
inductance and the open circuit shall have negligible capacitance. The load resistor shall have a
value close (within 1 %) to the nominal impedance of the CUT (e.g. 100 Ω) and with negligible
inductance and capacitance. The connection cable shall be as short as possible and well matched to
the nominal impedance;
— Resistor termination networks (RTN) for termination of inactive pairs. The resistor termination
network shall provide the differential mode and the common mode reference termination
impedances. It is recommended to use resistor termination networks in accordance with
EN 50289-1-11:2016, Annex C. Baluns may be used for termination of the inactive pairs if they
provide the specified differential and common mode terminations.
4.2.2.2 Test sample
The cable under test (CUT) shall have a length of at least 10 m, if not stated otherwise. The maximum
sample length shall be such that the attenuation at the highest me
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