電磁兼容及其保護(hù)前言.ppt

1、Fundamentals of Electromagnetic Compatibility and Electromagnetic Environment Protection,Teaching material,Fundamental of Electromagnetic Compatibility and Application Zhao Yang, China Machine Press, 2006.3,Reference books,Introduction to Electromagnetic Compatibility Clayton R. Paul, John Wiley & S

2、ons, Inc. 1992 Electromagnetic Compatibility: Principles and Applications （Chinese Version） D. A. Weston, Marcel Dekker,1,With the wide spread use of high-speed digital-operated electronic devices, especially the exponential growth in wireless communications such as Bluetooth, GSM Mobile, WLAN, UWB,

3、 and so on, without proper control, these devices will be interrupted by the Electromagnetic Interference (EMI).,About this course,If EMI are not discovered until product testing occurs. The resolution of interference problems of product development often involves additional components which add to

4、systems cost and complexity.,It is to be face the Electromagnetic Compatibility (EMC).,2,The understanding of the behavior of electronic devices and systems requires that of Maxwells equations and signal analysis techniques. However, such application is often cumbersome. To avoid this complexity, an

5、 approximate analysis technique is electric circuit theory at low frequency. For example, Kirchoffs Voltage Law (from Faradays Law) and Kirchoffs Current Law (from Amperes Law).,3,EMC involves the operation of these and other familiar devices in a regime where the special cases and simplifications t

6、hat are associated with normal behavior break down, and requires one to return to a more fundamental set of rules to describe the behavior of these devices.,Non-ideal behavior implies that devices are functioning in an abnormal way, when they are really behaving in a perfectly natural way. It is onl

7、y through the application of fundamental principles that the behavior of devices under all operating conditions is predictable.,About this course,4,For instance, it is impossible to know where certain electronic devices such as notebook computers will be operated. Notebooks are commonly used in the

8、home, in automobiles, at construction sites, onboard airplanes, and even aboard manned spacecraft in Earth orbit. Each of these environments presents unique hazards and also requires a variety of emission limits. The same notebook computer must be designed to function in the presence of a hair dryer

9、, and also cannot interfere with the instrument landing system of a commercial airliner.,5,characteristic of this course,Based on theory of electromagnetic field A new, cross subject Particularity of units Concepts and terms coming from radio technology Practicability Rely on measurement intensively

10、,6,Why we need to learn EMC?(1),Jul. 29, 1967 - Fire broke out on the deck of USS Forrestal CV 59 in Gulf of Tonkin during Vietnam War and cause 134 dead, 161 injured.,On May 4th,1982 The destroyer HMS Sheffield was hit by an missile. Many soldiers were killed.,Disasters caused by lightning,Disaster

11、s caused by ESD (Electrostatic Discharge ),7,tweezers,The debugging of electronic device is more difficult.,The obliged actualization of EMC standards,The competition shortened the period of development,Why we need to learn EMC?(2),8,EMC is necessary,9,Why debugging,Signal distortion,Cant achieve ex

12、pect function,Electromagnetic Compatibility,Signal Integrity,10,Electromagnetic Interference,11,Interference Source,12,There are four basic coupling mechanisms: conductive, capacitive, magnetic (inductive) , and radiative. Any coupling path can be broken down into one or more of these coupling mecha

13、nisms working together. For example the lower path in the diagram involves inductive, conductive, capacitive modes.,13,So the ways of coupling electromagnetic energy from a source to a receptor are:,1. Conducted (electric current) 2. Inductively coupled (magnetic field) 3. Capacitively coupled (elec

14、tric field) 4. Radiated (electromagnetic field),Some Types of EMC Problem Excessive RF Emissions Susceptibility (Immunity) ESD (Electrostatic Discharge ),Coupling paths, often utilize a complex combination of these methods, making the path difficult to identify even when the source and receptor are

15、known. There may be multiple coupling paths and steps taken to attenuate one path may enhance another.,14,Ways to solve,Conductor radiation The conductors (tracks, component leads) on the circuit that are not grounded will be acting as antennae, radiating RF energy. By keeping these conductors short

16、 and running them close to grounded areas, they become less efficient and will emit less Suppression components Suppression components for broadband sources: capacitors, varistors Grounding For emissions problem: shielding,15,Other ways,Power Supply Bus Design Signal Track Design Printed Circuit Boa

17、rd （PCB） and Component Layout Circuit Design Techniques,16,EMC Education,Introduction to Electromagnetic Interference (EMI) and its Effects EM Waves Radiation Mechanisms and practical antennas The EMC Directive, implementing regulations and EMC Standards Measurement Environments and testing, includi

18、ng the Open Field Test Site and Anechoic Chamber.,17,EMC Education,Measurement and Measurement Systems (receivers and spectrum analyzers) Overview of EMC Design Principles Conducted Interference - Suppression Techniques Crosstalk Power Supplies - EMC Considerations EMC on a PCB Shielding demonstrate

19、d using Computational Electromagnetics/ EMC prediction software,18,Research advances,Parasitic Inductance, Capacitance and Resistance in Circuits Time Domain Circuit Analysis High-Speed, Time Domain Measurements Crosstalk in Cables and Printed Circuit Boards Properties of High-Speed Logic Families D

20、ifferential Signaling,19,Research advances,Power Dissipation in Devices and Circuits Time Domain Transmission Line Analysis High-Frequency Measurements Proper Grounding Strategies Printed Circuit Board Decoupling Printed Circuit Board Layout New Hardware and Software Technologies,20,Computer Softwar

21、e,AnSys Inc. FEKO (EM Software & Systems - S.A. (Pty) Ltd. The name is derived from the German, which can be translated as Field Calculations for Bodies with Arbitrary Surface. ) Apsim （Applied Simulation Tech） Compact (Computerized Optimization of Microwave Passive and Active CircuiTs) CST (Compute

22、r Simulation Technology ) XFDTD （REMCOM）,21,EMC Test Equipment,Antenna Signal Generator LISN ( an abbreviation for Line Impedance Stabilization Network) Network Analyzer,22,EMC Equipment Producer,Rohde & Schwarz Agilent Technologies Teseq National Instruments,EMC Testing - How to do It,Radiated emis

23、sion testing on the open field test site, (eg. EN55011, EN55022) Conducted emission testing using the absorbing clamp (EN55014) Conducted emission testing using a LISN (eg. EN55011, EN55022) Conducted immunity - electrical fast transient/burst, (EN61000-4-4) Conducted RF immunity, (EN61000-4-6) Radi

24、ated immunity testing in an anechoic chamber, (EN61000-4-3) Electrostatic discharge testing, (EN61000-4-2),23,International Electrotechnical Commission (IEC), has several committees working full time on EMC issues. These are: Technical Committee 77 (TC77), working on electromagnetic compatibility be

25、tween equipment including networks. Comit International Spcial des Perturbations Radiolectriques (CISPR), or International Special Committee on Radio Interference. The Advisory Committee on Electromagnetic Compatibility (ACEC) co-ordinates the IECs work on EMC between these committees. International

26、 Organization for Standardization (ISO) promotes worldwide proprietary, industrial and commercial standards.,Organizations and standards of EMC,24,Europe: Comit Europen de Normalisation (CEN) or European Committee for Standardization). European Telecommunications Standards Institute (ETSI). United S

27、tates: The Federal Communications Commission (FCC). Britain: The British Standards Institution (BSI).,Organizations and standards of EMC,25,EMC related publications,IEEE transaction on EMC, Antenna and Propagation IEEE Press Cable Shielding for Electromagnetic Compatibility Anatoly Tsaliovich, Van N

28、ostrand Reinhold, 1995. Capacitance, Inductance and Crosstalk Analysis Charles S. Walker, Artech House, 1990. Electromagnetic Compatibility: Principles and Applications D. A. Weston, Marcel Dekker, 1991. Electromagnetic Compatibility J.J. Goedbloed, Prentice Hall, 1992. Some Chinese Books on EMC.,26

29、,On July 29, 1967, the U.S. aircraft carrier Forrestal was deployed off the coast of North Vietnam. The carrier deck contained numerous attack aircraft that were fueled and loaded with 1000-pound (lb) bombs, as well as air-to-air and air-to-ground missiles.,One of the aircraft missiles was inadverte

30、ntly deployed, striking another aircraft and causing an explosion of its fuel tanks and the subsequent death of 134 service people. The problem was thought to be caused by the generation of radiofrequency (RF) voltages across the contacts of a shielded connector by the ships high-power search radar.

31、,In 1982 the United Kingdom lost a destroyer, the HMS Sheffield, to an Exocet missile during an engagement with Argentinian forces in the battle of the Falkland Islands. The destroyers radio system for communicating with the United Kingdom would not operate properly while the ships antimissile detec

32、tion system was being operated due to interference between the two systems. To temporarily prevent interference during a period of communication with the United Kingdom, the antimissile system was turned off. Unfortunately, this coincided with the enemy launch of the Exocet missile.,The Hindenburg d

33、isaster has been attributed to spark discharge,Anechoic chamber,Close-up of a pyramidal RAM,Antenna,Biconical antenna,Omnidirectional biconical antenna,LISN ( an abbreviation for Line Impedance Stabilization Network),a standard LISN with top cover removed,LISN block diagram. This is standard diagram

34、 of a typical LISN. Part values for a particular standard (MIL-STD 461E): C1=8F, R1=5, C2=250nF, R2=1k,network analyzer (an instrument used to analyze the properties of electrical networks, especially those properties associated with the reflection and transmission of electrical signals known as sca

35、ttering parameters (S-parameters),ZVA40 vector network analyzer from Rohde & Schwarz.,Agilent Technologies, or Agilent, is an American company that designs and manufactures electronic and bio-analytical measurement instruments and equipment for measurement and evaluation.,Agilents major product line

36、s include: Electronic Test and measurement products such as oscilloscopes, logic analyzers, signal generators, spectrum analyzers, vector network analyzers, atomic force microscopes (AFM), automated optical inspection, automated X-ray, in-circuit test, and electronic design automation (EDA) software

37、,Agilent Technologies headquarters lobby in Santa Clara, California,BACK,ANSYS, Inc. is an engineering simulation software (computer-aided engineering, or CAE) developer headquartered south of Pittsburgh in the Southpointe business park in Cecil Township, Pennsylvania, United States. It was founded

38、in Canonsburg, Pennsylvania, U.S. in 1970. It has many products including ANSYS Multiphysics, Fluent, Workbench, HFSS, SIWave, SpaceClaim.,FEKO is a computational electromagnetics software product developed by Altair Engineering. It is a general purpose 3D electromagnetic (EM) simulator. FEKO origin

39、ated in 1991 at the University of Stuttgart, Germany. The software is based on the Method of Moments (MoM) integral formulation of Maxwells equations and various hybrid methods such as: (FEM) / MoM , MoM / PO (Physical Optics) , MoM /GO (Geometrical Optics), MoM /UTD (Uniform Theory of Diffraction).

40、,Rohde & Schwarz GmbH & Co KG is an international electronics group specialized in the fields of electronic test equipment, broadcasting, radiomonitoring and radiolocation, and radio communication. The company provides products for the wireless communications, broadcasting and electronics industry,

41、aerospace and defense, homeland security and critical infrastructures. The group has been developing, producing and marketing electronic products for the capital goods sector since 1933. In addition to the Munich headquarters, there are regional headquarters in the US (Columbia, Maryland) and in Asi

42、a (Singapore). Outside Germany, Rohde & Schwarz has development centers in the US, Singapore, Korea, China, Denmark, France and Great Britain. The company has also production facilities in Singapore and Malaysia.,Back,Teseq AG, formerly Schaffner Test Systems is a supplier of Electromagnetic compati

43、bility (EMC) test solutions. They develop and manufacture instruments for EMC emissions and immunity testing both for radiated and conducted emissions and immunity. Teseq operates ISO 17025 accredited calibration laboratories with EMC specialization. Teseq was twice nominated for Best in Test by Tes

44、t & Measurement World Magazine and has been awarded A2LA certification. They delivered over 10,000 electrostatic discharge (ESD) simulators. Teseq equipment may be found in most EMC test laboratories. Teseq, formerly Schaffner Test Systems was the first company to recognize the threat of EMC emissions and interference and begin offering EMC instruments.,Back,National Instruments Corporation, or NI, is an American company with international operation. Headquartered in Austin, Texas, it is a producer of automated test equipment and virtual in