1、 ECMA-358 1stEdition / December 2004 ICT Product Radiated Emissions: 16 GHz Standard ECMA-358 1stEdition / December 2004 ICT Product Radiated Emissions: 16 GHz Ecma International Rue du Rhne 114 CH-1204 Geneva T/F: +41 22 849 6000/01 www.ecma-international.org IW ECMA-358.doc 20.01.2005 10:17 . Brie
2、f history A special working group within Ecma TC20 has prepared this Standard. It integrates the existing requirements from CISPR 22 for general test setup and the current work from CISPR/A on measurement methods and test site validation methods above 1 GHz. This document also establishes limits fro
3、m 1 to 6 GHz, which provide reasonable protection to communication services while remaining technically feasible and economically viable. This Ecma Standard has been adopted by the General Assembly of December 2004. Table of contents1 Scope 1 2 Conformance 1 3 References 1 3.1 Normative references 3
4、.2 Informative references 4 Definitions 1 4.1 Equipment Under Test (EUT) 4.2 Highest internal source frequency (fs) 2 4.3 ITE 2 5 Minimum upper test frequency 6 Limits for radiated emissions in the frequency range of 1 GHz to 6 GHz 2 7 Measurement distance 8 Antenna height requirements and other mea
5、surement configuration considerations 3 9 Measurement instrument detectors 9.1 Noise impulse peak detection 10 Test set-up and operating conditions of the EUT 3 11 Measurement procedure 12 Final measurement procedure 13 Measurement site validation Annex A (informative) Test table considerations 5 -
6、i - 1 Scope This Standard specifies measurement methods and limits for radiated emissions from Information and Communication Technology (ICT) equipment in the frequency range of 1 GHz to 6 GHz. This Standard is based on CISPR 22, which classifies ICT equipment into class A and class B ITE. This Stan
7、dard provides: Uniform measurement requirements for radiated emissions; Standardized operating conditions and interpretation of results; Limits of disturbance. 2 Conformance Radiated emissions from conforming ITE, measured according to the conditions, procedures and requirements specified herein, do
8、 not exceed the limits specified in this Standard. 3 References 3.1 Normative references For application of this Ecma Standard, the latest edition of the documents listed below shall be used. CISPR 16-1-X series Specification for radio disturbance and immunity measuring apparatus and methods Part 1:
9、 Radio disturbance and immunity measuring apparatus CISPR 22: 4thEdition: Information technology equipment Radio disturbance characteristics Limits and methods of measurement For application of this Ecma Standard, the published CISPR standards, following approval of the CISPR/A working documents lis
10、ted below, shall be used. CISPR/A/485 Receiver Specifications to 18 GHz (proposed amendment to CISPR 16-1-1) CISPR/A/504 Measurement methods above 1 GHz (proposed amendment to CISPR 16-2-3) CISPR/A/500 Site Evaluation above 1 GHz CISPR/A/531 Site Evaluation above 1 GHz (proposed amendment to CISPR 1
11、6-1-4) 3.2 Informative references For emission limits in this Ecma Standard, these CISPR/I documents were used: CISPR/I/65 Emission limits and methods of measurement from 1 to 6 GHz CISPR/I/105 Emission limits and methods of measurement form 1 to 6 GHz (proposed amendment to CISPR 22) 4 Definitions
12、4.1 Equipment Under Test (EUT) Representative ITE from which radiated emissions are measured. - 1 - 4.2 Highest internal source frequency (fs) The highest frequency generated or used within the EUT or on which the EUT operates or tunes. 4.3 ITE Information Technology Equipment as defined and classif
13、ied in CISPR 22. 5 Minimum upper test frequency Radiated emissions from EUT shall be measured at the minimum upper test frequencies for the highest internal source frequency (fs) as specified in Table 1. Table 1 - Upper Frequency of Measurement Highest internal source frequency fs(MHz) Radiated Emis
14、sions minimum upper test frequency (MHz) fs1000 the lesser of: 5 fsor 6000 6 Limits for radiated emissions in the frequency range of 1 GHz to 6 GHz Radiated emissions shall not exceed the limits shown in Table 2. The limits are based on a test distance of 3 meters. If the reading on the measuring re
15、ceiver shows fluctuations close to the limit, the reading shall be observed for at least 15 seconds at each measurement frequency; the highest reading shall be recorded, with the exception of any brief isolated high reading, which shall be ignored. Table 2 - Limits for radiated emissions Class B ITE
16、 Class A ITE Frequency Range (MHz) Peak Limit (dBV/m) Average Limit (dBV/m) Peak Limit (dBV/m) Average Limit (dBV/m) 1000 f 6000 70 54 76 60 7 Measurement distance Radiated emissions limits for frequencies above 1 GHz are based on a measurement distance of 3 meters. Measurements at 3 meters are pref
17、erred. Measurements may be made at a distance other than 3 meters provided: The measurement distance shall be at least 1 meter but not greater than 10 meters. - 2 - The limits are adjusted assuming free space propagation; that is, Ladj= L3m+ 20 Log(3/d) where: Ladj= adjusted limit (dBV/m) L3m= limit
18、 at 3 meter measurement distance (dBV/m) d = measurement distance between the periphery of the EUT volume and the receive antenna reference point (meters) In case of dispute, the measurement distance used during the original assessment of the EUT shall take precedence. NOTE Comparison of measurement
19、s at different distances extrapolated to a common distance (e.g. 3 meters) will not correlate as well as measurements made at the same test distance. 8 Antenna height requirements and other measurement configuration considerations The measurement configuration shall be consistent with CISPR/A/504. 9
20、 Measurement instrument detectors Measurements shall be made with both peak detectors and linear average detectors. Detector specifications shall be in-line with CISPR/A/485 and CISPR/A/504. 9.1 Noise impulse peak detection The peak detector limits shall not be applied to noise from arcs or sparks t
21、hat are high-voltage air breakdown events. Such noise arises when EUT contains or controls mechanical switches that control current in inductors, or when EUT contain or control subsystems that create static electricity (such as paper handling devices). The average limits apply to noise from arcs or
22、sparks, and both peak and average limits will apply to other noise from such EUT. 10 Test set-up and operating conditions of the EUT Test set-ups and operating conditions of the EUT shall be consistent with CISPR/A/504. Consult Annex A for test table material selection. 11 Measurement procedure It i
23、s recommended to perform a preliminary measurement, as described in CISPR/A/504. 12 Final measurement procedure Final measurements shall be performed as described in CISPR/A/504. 13 Measurement site validation Site validation shall be performed in accordance with CISPR/A/531. - 3 - - 4 - Annex A (in
24、formative) Test table considerations To reduce measurement errors due to reflections from the test table, a low reflectivity material should be used. Test tables made from wood, glass fiber, reinforced plastic are significantly reflective at frequencies above 1 GHz and are therefore not suitable in
25、this application. Materials with a dielectric constant 1.25 such as expanded polystyrene (Styrofoam) is recommended. Table A1 - Dielectric Constants of Various Materials Material Min Max Air 1.0 1.0Styrofoamtm1.03 1.03 Wood (dry) 1.4 2.9 Paper 1.5 3.0 Polystyrene 2.4 3.0Lucitetm2.5 2.5 Polyethylene 2.5 2.5Amber 2.6 2.7 Plexiglass 2.6 3.5Ebonitetm2.7 2.7 Polycarbonate 2.9 3.2Epoxy Resin 3.4 3.7 Polyimide 3.4 3.5 Formicatm3.6 6.0Glass 3.8 14.5 Bakelitetm5.0 22.0 - 5 -
