1、ANSI C63.22-2004IEEE StandardsC63.22American National StandardGuide for Automated ElectromagneticInterference Measurements3 Park Avenue, New York, NY 10016-5997, USAAccredited by the American National Standards InstituteSponsored by theAccredited Standards Committee on Electromagnetic Compatibility,
2、 C63IEEE Standards22 December 2004Print: SH95290PDF: SS95290ANSI C63.22-2004 American National Standard Guide for Automated Electromagnetic Interference Measurements Accredited Standards Committee on Electromagnetic Compatibility, C63 accredited by the American National Standards Institute Secretari
3、at Institute of Electrical and Electronics Engineers, Inc. Approved 24 June 2004 American National Standards Institute Reaffirmed 22 October 2012 American National Standards InstituteAbstract: U.S. consensus guideline for automation of conducted and radiated EMI compliance measurements is provided i
4、n this guide. This document does not include mandatory specifications for automation tools (i.e., application software, automated test equipment, computers and periph- erals). Where possible, the guidance provided herein is harmonized with other national and inter- national standards used for simila
5、r purposes. Keywords: conducted emissions, data analysis tools, data handling, exploratory measurements, facility integrity, final measurements, prescans, probability of signal intercept, radiated emissions, sweep times, scan rates The Institute of Electrical and Electronics Engineers, Inc. 3 Park A
6、venue, New York, NY 10016-5997, USA Copyright 2004 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 22 December 2004. Printed in the United States of America. IEEE is a registered trademark in the U.S. Patent +1-978-750-8400. Permission tophotocopy portio
7、ns of any individual standard for educational classroom use can also be obtained throughthe Copyright Clearance Center.iiiCopyright 2004 IEEE. All rights reserved.IntroductionThis introduction provides some background on the rationale used to develop this guide. This information ismeant to aid in th
8、e understanding and usage of this guide.This guide describes, in general terms, the use of automatic test equipment and the automation of measure-ments of electromagnetic emissions. It is intended for the following: Individuals or organizations who plan on automating Electromagnetic Interference (EM
9、I) measure-ments and acquire that application software from a supplier. Individuals or organizations who acquire EMI application software from a developer for resale toother individuals or organizations. Individuals or organizations who determine the feature set for EMI application software. Individ
10、uals or organizations who perform automated EMI measurements. Software suppliers interested in providing high-quality software to acquirers.This guide is designed to help individuals or organizations: Determine the appropriate feature set of EMI automation software Validate the settings of software
11、parameter used to perform measurements Determine requirements for test equipment to be used in an automated system Determine characteristics of automated test systems for a given test environmentThis guide is intended to satisfy the following objectives: Promote consistency within organizations in a
12、cquiring third-party software from software suppliers Provide useful guidelines for the implementation of automated test systems Provide useful practices on the determination of necessary software features to automate specifictests Provide useful practices on the use of software tools for data acqui
13、sition and data analysis purposes Assisting individuals and organizations judging the quality and adequacy of supplier softwareThe following individuals contributed to the preparation of this guide:Werner Schaefer, ChairEd ChadwickRobert Crawhall Robert HofmannChris Kendall Art LightSiegfried Linkwi
14、tz Dean PaulusPatrick RichardsonWilliam ScrivnerPaul Sikora Roger SouthwickBarry Wallen Norman WehlingMichael Windler John WyncottStan XavierThis introduction is not part of ANSI C63.22-2004, Guide for Automated Electromagnetic InterferenceMeasurements.ivCopyright 2004 IEEE. All rights reserved.At t
15、he time that the Accredited Standards Committee on Electromagnetic Compatibility, C63, approved thisguide, it had the following membership:Ralph M. Showers, ChairDonald N. Heirman, Vice-ChairRobert L. Pritchard, SecretaryOrganization Represented RepresentativeAlliance for Telecommunications Industry
16、 Solutions (ATIS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. Chrysanthou J. TurnerAmerican Council of Independent Laboratories (ACIL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. VioletteW. StumpfAmerican Radio Relay League (ARRL). . . . . . . . . .
17、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. BodsonE. HareCurtis-Straus LLC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J. CurtisJ. StewartDell, Inc. . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E. BronaughR. B. WallenETS-Lindgren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. FoegelleZ. C
19、henFederal Communication Commission (FCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W. HurstA. WallFood and Drug Administration (FDA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J. CasamentoJ. L. Silb
20、ergergHewlett-Packard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . K. HallInformation Technology Industry Council (ITIC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J. HirvelaJ.
21、 RosenbergIEEE (Institute of Electrical and Electronics Engineers, Inc.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. N. HeirmanIEEE Electromagnetic Compatibility Society . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S. BergerD. SweeneyLuce
22、nt Technologies Bell Labs Innovations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. MoogilanNational Institute of Standards it includes the ground plane, weatherprotection, shielding, absorbers, support structures, and surroundings as well as ambient sign
23、als.3.16 sweep time: The time required by the measuring instrument to electronically tune across a selected frequency span.4. General guidelines for automated measurementsCare should be taken by the automated test system designer in obtaining a thorough understanding of all elements of the measureme
24、nt process, as well as of the measurement system to be used in the datacollection process. The performance of a measurement with a lack of such knowledge may result in theacquisition of erroneous and/or invalid data.The general automated test system can be divided into four distinct sections. These
25、are 1) the transducerand signal conditioning section, 2) the verification section, 3) the signal measurement section, and 4) the control and data processing section. Though identified as separate entities for clarity in this document (see Figure 1), it should be noted that in many modern EMI test sy
26、stems, a single equipment item may containelements of multiple sections as identified here.Copyright 2004 IEEE. All rights reserved. 4 ANSI C63.22-2004Guide for Automated Electromagnetic Interference MeasurementsFigure 14.14.2Elements of an automated radiated emission test systemTransducer and signa
27、l conditioning section The transducer and signal conditioning section of the system consists of all elements that are placed in frontof the input connector of the EMI receiver. The function of this section of the system is to intercept themaximum signal levels emitted from the EUT, and transmit this
28、 energy to the receiver in a measurableform. These elements can include antennas or line impedance stabilization networks (LISNs), cables, the antenna selection RF switch (if multiple antennas are used to cover the appropriate frequency range), andany preamplifiers or attenuators (external to the EM
29、I receiver) necessary to bring the signal levels to bemeasured to within the dynamic range of the receiver. In addition, included in this section is the antennatower, and the EUT turntable, which are used to determine the maximum emission levels based on antennaheight and polarization as well as EUT
30、 orientation relative to the measuring antenna.Verification sectionThe verification section of the emissions measurement system is necessary to ensure that data is collected with a functioning test system and the required tolerances, as per the applicable test specification, are met.The verification
31、 section consists of a stable signal source, which should be traceable to national calibrationstandards (e.g., NIST or other local standards reference organization), the associated cabling, and adedicated manual or automated procedure. The verification procedure presents a means of quicklydemonstrat
32、ing that most elements of the measurement system, from the transducer output port to the datapresentation, perform within previously defined tolerances that are acceptable by the standard to whichtesting is being performed. It should be noted that this process is not intended to be a detailed true t
33、est ofthe performance characteristics of the receiving system, but merely a means to check the tolerance of theCopyright 2004 IEEE. All rights reserved. 5 ANSI C63.22-2004Guide for Automated Electromagnetic Interference Measurementsfrequency and amplitude calibration. It does not address many additi
34、onal and important EMI receiverparameters.A verification signal can be generated by a stand-alone signal generator, a receivers tracking generator, ora calibrated impulse generator. Verification, in its most simplified form, is performed by disconnecting theRF coaxial cable from the systems receivin
35、g transducer, and connecting it to the verification signal source.The generators output frequency shall be tuned over the measurement frequency range of interest and itssignal amplitude is measured by the EMI receiver. By comparing the current results with previouslyrecorded and verified data, test
36、system malfunctions can be identified quickly and a determination made ifthe resultant data still meets required tolerances. Once the verification process has been completed, thesignal source is disconnected, and the systems receiving transducer reconnected.4.34.44.5EMI receiver section The EMI rece
37、iver section of the system consists of one or multiple instruments that perform the actualsignal measurement. Specifically, the EMI receiver shall have performance characteristics that meet therequirements of ANSI C63.2-1996 and/or CISPR 16 1-1 (2003). In addition, the receiver shall sufficientlymee
38、t the actual requirements for testing an EUT to the applicable regulations, especially in regard to thenecessary sensitivity and frequency accuracy.Control and data processing section The control and data processing section of the automated measurement system takes many forms. First, anyautomated co
39、ntrol system within the receiver section shall be considered as a part of this section. Thisincludes not only instrument firmware-controlled processor systems, but any software that can be inputdirectly into the receivers memory, and thereby operates as an onboard control system. Secondly, this area
40、includes external controllers or computers along with their application software. Finally, consideration shallbe given to the data storage and output devices like printers or plotters that are a part of the overall system.The quality and resolution of the graphical test data presentation, as well as
41、 any tabular information shallmeet the requirements of the applied standards and the overall measurement goal (e.g., visual comparisonof different sets of data resulting from EUT modifications).Precautions for automating EMI measurementsMuch of the tedium of making repeated EMI measurements can be r
42、emoved by automation. Operator errorsin reading and recording measurement values are minimized. By using a computer to collect data, though,new forms of errors can be introduced that may have been detected by an operator. In some situations,automated testing can lead to greater measurement uncertain
43、ty in the collected data than manualmeasurements performed by a skilled operator. Fundamentally, there is no difference in the accuracy withwhich an emission value is measured whether manually or under software control. In both cases, themeasurement uncertainty is based on the accuracy specification
44、s of the components used in the test setup.Difficulties may arise, though, when the actual measurement situation is different from the scenarios forwhich the software was designed.For example, an EUT emission adjacent in frequency to a high-level ambient signal may not be measuredaccurately, if the
45、ambient signal is present during the time of the automated test. A knowledgeable tester,however, is more likely to distinguish between the actual interference and ambient signal; therefore, themethod for measuring the EUT emission can be adapted as required. However, performing ambient scans prior t
46、o the actual emission measurement with the EUT turned off to record ambient signals present on theOATS can sometimes save valuable test time. In this case, the software may be able to warn the operator of the potential presence of ambient signals at certain frequencies by applying appropriate signal
47、 identificationalgorithms.Copyright 2004 IEEE. All rights reserved. 6 ANSI C63.22-2004Guide for Automated Electromagnetic Interference MeasurementsIn a situation where the EUT emission is slowly varying in amplitude, the software may not have been setup for a sufficiently long dwell time at the emis
48、sion frequency to capture its peak amplitude. By knowingor observing the emission characteristics of the EUT during an overview measurement, the operator will beable to specify the relevant frequency scan parameters during software setup for the final test. Testing an EUT with a low on-off cycle can cause problems in regard to the probability of intercepting itsemissions. If the EMI receiver is tuned to frequencies where no EUT emissions occur during the on-cycle,no emissions are recorded. Therefore, multiple scans may be necessary using a “maximum hold”
