Vehicles|| boats and internal combustion engines―Radio disturbance characteristics―Limits and methods of measurement for the protection of on-board receivers
GB/T 18655-2025 Vehicles, boats and internal combustion engines—Radio disturbance characteristics—Limits and methods of measurement for the protection of on-board receivers
This document contains limits and test procedures for the measurement of radio disturbances in the frequency range of 150 kHz to 5 925 MHz. This document applies to vehicles, boats, trailers, internal combustion engines, devices and any electronic/electrical component intended for use in vehicles, boats, trailers and devices. Refer to International Telecommunications Union (ITU) publications and and the practical application in China for details of frequency allocations . The limits are intended to provide protection for on-board receivers installed in a vehicle from disturbances produced by components/modules in the same vehicle.
The receiver types to be protected are, for example, broadcast receivers (sound and television), land mobile radio, radio telephone, amateur, citizens' radio, satellite navigation (Beidou, GPS etc.), Wi-Fi, V2X, and Bluetooth.
This document does not include protection of electronic control systems from radio frequency (RF) emissions or from transient or pulse-type voltage fluctuations. These subjects are included in other publications of SAC.
The limits in this document are recommended and subject to modification as agreed between the customer (e.g. vehicle manufacturer) and the supplier (e.g. component manufacturer). This document is also intended to be applied by vehicle manufacturers and suppliers which are to be added and connected to the vehicle harness or to an on-board power connector after delivery of the vehicle.
This document defines test methods for use by vehicle manufacturers and suppliers, to assist in the design of vehicles and components and ensure controlled levels of on-board radio frequency emissions.
The emission requirements in this document are not intended to be applicable to the intentional transmissions from a radio transmitter as defined by the ITU including their spurious emissions.
Note 1: This exclusion is limited to those intended transmitter emissions, which leave the EUT as radiated emissions and are coupled onto the wire line in the measurement setup. For conducted transmissions on frequencies intentionally produced by the radio part of an EUT, this exclusion does not apply.
Note 2: It is usual for customers and suppliers to use radio regulation standards to manage the effect of spurious emissions from a radio transmitter unless limits of spurious emission are agreed in the test plan.
Note 3: See Annex A for the applicability checking process
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.
GB 1002 Single phase plugs and socket-outlets for household and similar purposes—Types, basic parameters and dimensions
GB/T 2099.1 Plugs and socket-outlets for household and similar purposes—Part 1: General requirements
GB/T 4365-2024 Electrotechnical terminology—Electromagnetic compatibility
GB/T 6113.101 Specification for radio disturbance and immunity measuring apparatus and methods—Part 1-1: Radio disturbance and immunity measuring apparatus—Measuring apparatus
GB/T 6113.102-2018 Specification for radio disturbance and immunity measuring apparatus and methods-Part 1-2:Radio disturbance and immunity measuring apparatus-Coupling devices for conducted disturbance measurements
GB/T 9254.1-2021 Information technology equipment, multimedia equipment and receivers—Electromagnetic compatibility—Part 1: Emission requirements
GB/T 19596-2017 Terminology of electric vehicles
GB/T 29259-2012 Road vehicle - Electromagnetic compatibility terminology
GB/T 44119-2024 Measurement method of antenna factor for 1m method radiated disturbance
3 Terms and definitions
For the purposes of this document, the following terms and definitions and those specified in GB/T 4365-2024, GB/T 19596-2017 and GB/T 29259-2012 apply.
3.1
antenna matching unit
device used to form/realize impedance matching with a measuring instrument with impedance of 50Ω within the antenna measurement frequency range
[Source: GB/T 29259-2012, 3.66]
3.2 artificial mains network; AMN
network that provides a defined impedance to the EUT at radio frequencies, couples the disturbance voltage to the measuring receiver and decouples the test circuit from the supply mains
Note 1 to entry: There are two basic types of AMN, the V-network (V-AMN) which couples the unsymmetrical voltages, and the delta-network which couples the symmetric and the asymmetric voltages separately. The terms line impedance stabilization network (LISN) and V-AMN are used interchangeably.
Note 2 to entry: Network inserted in the power mains of the vehicle in charging mode or of a component (e.g. charger) which provides, in a given frequency range, a specified load impedance and which isolates the vehicle / component from the power mains in that frequency range.
3.3 artificial network; AN
network inserted in the supply lead or signal/load lead of apparatus to be tested which provides, in a given frequency range, a specified load impedance for the measurement of disturbance voltages and which can isolate the apparatus from the supply or signal sources/loads in that frequency range
Note 1 to entry: Network inserted in the DC power lines of the vehicle in charging mode which provides, in a given frequency range, a specified load impedance and which isolates the vehicle from the DC power supply in that frequency range.
[Source: GB/T 29259-2012, 3.52, modified]
3.4 asymmetric artificial network, AAN
network used to measure (or inject) asymmetric (common mode) voltages on unshielded symmetric signal (e.g. telecommunication) lines while rejecting the symmetric (differential mode) signal
Note to entry: This network is inserted in the communication/signal lines of the vehicle in charging mode or of a component (e.g. charger) to provide a specific load impedance and/or a decoupling (e.g. between communication/signal lines and power mains).
3.5 bandwidth
3.5.1 bandwidth of an equipment
the width of the frequency band outside which the level of any spectral component does not exceed a specified percentage of a reference level
[Source: GB/T 29259-2012, 3.18.1, modified]
3.5.2 bandwidth of signal
frequency bandwidth at which the level of any out-of-band spectral component does not exceed the specified percentage of the reference level
[Source: GB/T 29259-2012, 3.18.2 ]
3.6 boat
vessel intended to be used on the surface of water, its length being no greater than 15 m
[Source: GB/T 14023-2022, 3.2]
3.7
bonded
grounding connection with a DC resistance not exceeding 2,5 m ? and that provides the lowest possible impedance (resistance and inductance)
Note to entry: A low current (≤100 mA) 4-wire milliohm meter is recommended for this measurement.
3.8
broadband emission
emission which has a bandwidth greater than that of a particular measuring equipment or receiver. If the pulse repetition frequency (Hz) of signal is less than the measurement bandwidth of the instrument, it is also considered as a broadband emission.
3.9 charging mode
modes to supply power to an electric vehicle by connection of an electric vehicle to supply network (power supply)
Note: Mode 1, mode 2, mode 3 and mode 4 are also applicable to bi-directional charging.
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4 Requirements common to vehicle and component/module emissions measurement
4.1 General test requirements
4.1.1 Categories of disturbance sources (as defined in the test plan)
Electromagnetic disturbance sources can be divided into two main types:
---- narrowband sources (examples of narrowband disturbance sources are vehicle electronic components which include clocks, oscillators, digital logic from microprocessors and displays);
---- broadband sources (examples of broadband disturbance sources are electrical motors and ignition system).
NOTE 1: While most vehicle or electrical/electronic components are a source of both narrowband and broadband disturbances, some can be a source of only one type of disturbance.
NOTE 2: Broadband sources can be classified in short-duration broadband (examples are washer pump, door mirror, electrical windows) and long-duration broadband (examples are front wiper motor, heater blower, engine cooling).
For the purposes of this document, categorization of the disturbance type is used only in simplifying the testing demands by potentially reducing the number of detectors that shall be used (i.e. eliminating the average detector if the device is known to be broadband-type of source, such as a DC brush commutated motor). Otherwise, this document requires that sources comply with limits based upon both types of measurement detectors and not the type of disturbance.
4.1.2 Test plan
A test plan shall be established for each item to be tested. The test plan shall specify the frequency range to be tested, the emissions limits, antenna types and locations, test report requirements, supply voltage and other relevant parameters, including EUT operating conditions (as described in 4.1.4.)
The test plan shall define for each frequency band whether the conformance can be obtained with average and peak limits or with average and quasi-peak limits.
