GB/T 40675.2-2021Noise suppression sheet for digital devices and equipment - Part 2: Measuring methods (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1.Structure and Drafting Rules of Standardization Documents"

Drafting.

This document is Part 2 of GB/T 40675 "Noise Suppression Sheets for Digital Devices and Equipment". GB/T 40675 has been released

Lower part.

---Part 1.Definition and general performance;

---Part 2.Measurement methods;

---Part 3.Parameter characteristics of noise suppression film.

This document is equivalent to IEC 62333-2.2015 "Noise suppression sheets for digital devices and equipment Part 2.Measurement methods".

A chapter "Terms and Definitions" has been added to this document.

This document has made the following minimal editorial changes.

---Added formula number;

---Introduction is added before the items.

Introduction

The noise suppression sheet has the advantages of wide application frequency range, large operating temperature range, good electromagnetic noise suppression effect, and large thermal conductivity.

It is beneficial for applications in mobile phones, digital cameras, digital video cameras, notebook computers, scanners, CD/VCD, PDAs, car navigation systems, etc.

It is used to reduce the crosstalk between lines, reduce the electromagnetic induction coupling of connected circuits, reduce radiation, attenuate the induced current and attenuation on the LCD shielding layer.

Reduce the interference of the internal radio frequency circuit, reduce the mobile phone SAR radiant rate, etc. With the high frequency, miniaturization, integration and functionalization of electronic equipment

The development trend of noise suppression film is more and more widely used in digital devices and equipment.

GB/T 40675 "Noise suppression sheet for digital devices and equipment" consists of 3 parts.

---Part 1.Definition and general performance. Defines the electromagnetic field for digital devices and equipment with a frequency of 30MHz~30GHz.

The terms and definitions of the noise suppression film, and the effect of using the noise suppression film on the signal are given.

---Part 2.Measurement methods. The measurement method of the electromagnetic characteristics of the noise suppression sheet is specified. These measurement methods can suppress noise

The performance of the film is effectively and repeatedly measured to ensure that manufacturers and users can get the same measurement results.

---Part 3.Parameter characteristics of noise suppression film. Digital devices and equipment with a frequency of 30MHz~30GHz are given

Use electromagnetic noise suppression sheet (NSS) parameter characteristics.

GB/T 40675.2 specifies the test details of the parameters defined in GB/T 40675.1.The two parts are closely related and need to be coordinated

use.

GB/T 40675.2 can effectively and reproducibly test the performance of noise suppression films, and provide production and trading parties in the industry with

A unified measurement basis to ensure that manufacturers and their users can obtain the same measurement results, thereby helping to standardize production and trading in the industry

To promote the healthy and orderly development of the industry.

Noise suppression sheet for digital devices and equipment

Part 2.Measurement method

1 Scope

This document specifies the measurement method of the electromagnetic characteristics of the noise suppression sheet. These measurement methods can effectively measure the performance of the noise suppression sheet.

And it can be measured repeatedly to ensure that manufacturers and users can get the same measurement results.

2 Normative references

The content of the following documents constitutes an indispensable clause of this document through normative references in the text. Among them, dated quotations

Only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to

This document.

IEC 62333-1 Noise suppression sheet for digital devices and equipment Part 1.Definition and general performance (Noisesuppression

sheetfordigitaldevicesandequipment-Part 1.Definitionsandgeneralproperties)

Note. GB/T 40675.1-2021 Noise suppression sheet for digital devices and equipment Part 1.Definition and general performance (IEC 62333-1.2006, IDT)

CISPR16-1 Radio disturbance and immunity measurement equipment and measurement method specification Part 1.Radio disturbance and immunity measurement

Measuring equipment (Specificationforradiodisturbanceandimmunitymeasuringapparatusandmethods-Part 1.

Radiodisturbanceandimmunitymeasuringapparatus)

Note. GB/T 6113.101-2016 Radio disturbance and immunity measurement equipment and measurement method specification Part 1-1.Radio disturbance and immunity measurement

Measuring equipment (CISPR16-1-1.2010, IDT);

GB/T 6113.102-2018 Specification for Radio Disturbance and Immunity Measurement Equipment and Measurement Methods Part 1-2.Radio Disturbance and Immunity Measurement

Coupling device for measurement of conducted disturbance from measuring equipment (CISPR16-1-2.2014, IDT);

GB/T 6113.103-2021 Radio disturbance and immunity measurement equipment and measurement method specification Part 1-3.Radio disturbance and immunity measurement

Disturbance power of auxiliary equipment for measuring equipment (CISPR16-1-3.2016, IDT);

GB/T 6113.104-2016 Radio disturbance and immunity measurement equipment and measurement method specification Part 1-4.Radio disturbance and immunity measurement

Measuring antenna and test site for measuring equipment radiation disturbance (CISPR16-1-4.2012, IDT);

GB/T 6113.105-2018 Specification for Radio Disturbance and Immunity Measurement Equipment and Measurement Methods Part 1-5.Radio Disturbance and Immunity Measurement

Measurement equipment 5MHz~18GHz antenna calibration site and reference test site (CISPR16-1-5.2014, IDT);

GB/T 6113.106-2018 Radio disturbance and immunity measurement equipment and measurement method specification Part 1-6.Radio disturbance and immunity measurement

Calibration of EMC antennas for measurement equipment (CISPR16-1-6.2014, IDT).

CISPR22 Information technology equipment radio interference limits and measurement methods (Informationtechnology equipment-Radio

disturbancecharacteristics-Limitsandmethodsofmeasurement)

Note. GB/T 9254-2008 Information Technology Equipment Radio Disturbance Limits and Measurement Methods (CISPR22.2006, IDT)

3 Terms and definitions

There are no terms and definitions that need to be defined in this document.

4 General

The electromagnetic interference between electronic devices comes from the radiation of electronic devices, and part of it is the radiation generated by active devices driven by high frequency.