EMC设计基础（英文版）_2页.pdf

1-4244-0300-6/06/$20.00 2006 IEEE EMC DESIGN FUNDAMENTALS James Colotti(colotti)ABSTRACT Virtually every electronic device or system designed today is required to comply with EMC standards.Proper EMC design,throughout the development cycle,is necessary to cost-effectively ensure that products operate reliably in their intended electromagnetic environment without being susceptible to electrical noise from other devices,or generate excessive noise that can interfere with other devices.Meeting this goal has become especially challenging in recent years,due to the ever-growing use of electronics,increasing clock frequencies and escalading wireless-bandwidth demands.Products that do not comply with the applicable EMC requirements,can be blocked from markets,and/or can create interoperability issues with consequences ranging from a minor annoyance to death.EMC standards have been established by several agencies including the Federal Communication Commission(FCC),the US Military,the European Union(EU)and the Radio Technical Commission for Aeronautics(RTCA).Although numerous standards exist,they have a common fundamental theme;to establish a maximum limit on emissions and to establish a minimum level on susceptibility(immunity).To understand the impact of EMC on design,it is first necessary to understand the fundamental concepts of electromagnetic interference and electromagnetic compatibility.For an EMC problem to exist,three components are necessary:a source that generates the interference,a device that is susceptible to the interference,and a coupling path.The coupling path can be conducted(through power and/or signal lines)or radiated(magnetic,electric or plane wave).Fortunately several options exist for mitigating EMC issues.The effectiveness of the coupling path can be reduced(i.e.the isolation between the source and the susceptible device can be improved)through the use of increased separation,shielding,filtering,interconnection modifications,or a combination of these.Furthermore,the source can be modified to reduce the interference generated.Many of the techniques used to reduce the interference generated by the source can also be used to improve the immunity of the potentially susceptible device.These techniques include the routing of signals closer to ground planes and the operating frequency selection.System partitioning is also critical.Fundamentally,devices that are inherently noisy(such as power converters)should be located as far as practical from devices that require a low noise floor(such as wide dynamic range analog/digital converters).In larger/more-complex systems,signal and power distribution become an important component of the EMC design.An often-overlooked area is EMC design process.To cost-effectively ensure that products operate reliably in their specified electromagnetic environment,proper EMC practice must be considered throughout the development and manufacturing cycles.Since EMC can potentially affect all aspects of a product design(mechanical,electrical and system)it is often necessary to develop and maintain an EMC control plan that details the technical and administrative processes necessary to flow down the EMC requirements to all applicable portions of the product.AUTHORS BIOGRAPHY James Colotti is a Staff Analog Design Engineer for Telephonics,in Farmingdale New York.His most recent efforts include the design of low-cost receivers for Air Traffic Control(ATC)and Identification Friend or Foe(IFF)systems,and the design of a High Voltage Power Supply for the RDR Radar product line.Mr.Colotti is currently supporting the AN/APS-147 Multi-Mode Radar(MMR)program during its flight tests and transition into production.On the MMR,he was responsible for designing a 1 kW L-Band IFF Receiver/Transmitter,the power and signal distribution systems,and the EMI/EMC/TEMPEST.In the mid 1990s,Mr.Colotti was responsible for analog design activities on the AN/APX-103 AWACS IFF upgrade program.Other prior programs where James had analog/RF design responsibilities include the Multiple Access Beamforming Equipment(MABE)for the TDRSS Satellite,and the Portable Search Target Acquisition Radar(PSTAR).Specific design responsibilities typically involve high-speed/high-resolution A/D and D/A Conversion,analog signal processing,power conversion,1-4244-0300-6/06/$20.00 2006 IEEE power and signal distribution,EMI/EMC,and Receiver/Transmitters.In the late 1990s,as project engineer,Mr.Colotti was responsible for the development of an all-solid-state 5 kW L-Band Transmitter for another AWACS upgrade effort.In a similar capacity,he was also project engineer for an effort in the mid 1980s to develop a 2 kW Receiver/Transmitter for general ATC and IFF applications.Mr.Colottis patent award for the Dual Threshold Amplitude Detector was a result of technology developed on this program.In addition,he received a patent for the Synchronously Tuned Power Converter,which was developed during a digital receiver program.This patent dramatically reduces the effects of switching power converter noise in wireless/digital-receiver applications.In 2004,James Colotti received the IEEE Region 1 Award for New Technical Concepts.This Award cited the development of co-location techniques,which extend the capabilities of printed circuit board technologies.Since 2003,James has been the Chairman of the Microwave Theory and Techniques(MTT)Society of the IEEE Long Island Section.Throughout his career,James published several articles covering analog topics including power converters,digital-to-analog conversion,analog-to-digital conversion and receiver design.James graduated from Polytechnic Institute with a BSEE.He is a senior member of the IEEE,and is a certified Electromagnetic Compatibility Engineer,by the National Association of Telecommunications Engineers(NARTE).In his spare time,James enjoys tennis,traveling,playing the piano,listening to music(of various genres),skiing and bicycling.