OW-PASS FILTER HIGH-PASS FILTER 中·王 R RI RI UENCIES IN TH8非EcT1N PASSP REQUENCY BAND- PASS FILTER BAND-REJECT FILTER ECTION 脖 排 IN THIS SLCTtON THI3 SECTION Fe。 UENCY FIGURE 40.10 Filters provide a variety of frequency characteristics c 2000 by CRC Press LLC
© 2000 by CRC Press LLC FIGURE 40.10 Filters provide a variety of frequency characteristics
FERRITE TUBE 16mm(5/8in00×953mm3/8n)10 152mm (6 in. )LENGTH (3 in. )LENGTH 10 10 FIGURE 40.11 Ferrite provides a flexible means of achieving a low-pass filter with good high-frequency loss characteristics c FIGURE40.12 Transient responses are controlled using simple filters at the source (a) Resistance damping:(b)capacitance intended operational environment at designed levels of efficiency without causing or receiving degrada tion owing to unintentional electromagnetic interference. Electromagnetic compatibility is the result of an engineering planning process applied during the life cycle of the equipment. The process involves careful considerations of frequency allocation, design, procurement, production, site selection, installa- tion,operation, and maintenance. Electromagnetic pulse(EMP): A large impulsive-type electromagnetic wave generated by nuclear or chemical explosions
© 2000 by CRC Press LLC Electromagnetic compatibility (EMC): The capability of equipment or systems to be operated in their intended operational environment at designed levels of efficiency without causing or receiving degradation owing to unintentional electromagnetic interference. Electromagnetic compatibility is the result of an engineering planning process applied during the life cycle of the equipment. The process involves careful considerations of frequency allocation, design, procurement, production, site selection, installation, operation, and maintenance. Electromagnetic pulse (EMP): A large impulsive-type electromagnetic wave generated by nuclear or chemical explosions. FIGURE 40.11 Ferrite provides a flexible means of achieving a low-pass filter with good high-frequency loss characteristics. FIGURE 40.12 Transient responses are controlled using simple filters at the source. (a) Resistance damping; (b) capacitance suppression; (c) RC suppression; (d) diode suppression; (e) back-to-back diode suppression
Field strength: A general term that means the magnitude of the electric field vector(in volts per meter)or the magnitude of the magnetic field vector (in ampere-turns per meter). As used in the field of EMC/EMI the term field strength shall be applied only to measurements made in the far field and shall be abbreviated as FS. For measurements made in the near field, the term electric field strength(EFS) or magnetic field strength(MFS)shall be used, according to whether the resultant electric or magnetic field, respectivel netration: The passage through a partition or wall of an equipment or enclosure by a wire, cable, pipe, or other conductive object. Radio frequency interference(RFI): Synonymous with electromagnetic interference Shielding effectiveness: A measure of the reduction or attenuation in the electromagnetic field strength at a Signa Point in space caused by the insertion of a shield between the source and that point reference subsystem: This subsystem provides the reference points for all signal grounding to control static charges, noise, and interference. It may consist of any one or a combination of the lower frequency network, higher frequency network, or hybrid signal reference network. TEMPEST: A code word(not an acronym) which encompasses the government/industrial program for controlling the emissions from systems processing classified data. Individual equipment may be tEm PESTed or commercial equipment may be placed in shielded enclosures Related Topics 10.3 The Ideal Linear-Phase Low-Pass Filter. 10.4 Ideal Linear-Phase Bandpass Filters.55. 3 Dielectric References AFSC Design Handbook, DH1-4, Electromagnetic Compatibility, 4th ed, U.S. Air Force, Wright-Patterson Air Force Base, Ohio, January 1991 R. F. Ficchi, Ed,, Practical Design for Electromagnetic Compatibility, Hayden, 1971 R Freeman, Electromagnetic Compatibility Design Guide for Avionics and Related Ground Support equipment, Norwood, Mass. Artech House, 1982. L. H Hemming, Architectural Electromagnetic Shielding handbook, New York: IEEE Press, 1991 B Keiser, Principles of Electromagnetic Compatibility 3rd ed, Norwood, Mass. Artech House, 1987. Y.J. Lubkin, Filter Systems and Design: Electrical, Microwave, and Digital, Reading, Mass. Addison-Wesley, 1970 MIL-HDBK-419A, Grounding, Bonding, and Shielding of Electronic Equipment and Facilities, U.S. Department of Defense, Washington, D.C., 1990 R. Morrison, Grounding and Shielding Techniques in Instrumentation, New York: John Wiley, 1986 R. Morrison and W. H. Lewis, Grounding and Shielding Techniques in Facilities, New York: John wiley, 1990 T. Rikitake, Magnetic and Electromagnetic Shielding, Amsterdam: D Reidel, 1987 N. O. N. Violetto, Electromagnetic Compatibility Handbook, New York: Van Nostrand Reinhold, 1987 D.R. J. White, Shielding Design, Methodology and Procedures, Springfield, Va. Interference Control Technologies, D.R. J. White, A Handbook on Electromagnetic Shielding Materials and Performance, Springfield Va: Interference Control Technologies, 1975. Further Information The annual publication Interference Technology Engineers' Master(Item), published by R&B Enterprises, West Conshohocken, Pennsylvania, covers all aspects of EMI including an extensive product directory. The periodical IEEE Transactions on Electromagnetic Compatibility, which is published by The Institute of Electrical and Electronics Engineers, Inc, provides theory and practice in the EMI field The periodical EMC Test d- Design, published by the Cardiff Publishing Company, is a good source for practical EMI design informati c 2000 by CRC Press LLC
© 2000 by CRC Press LLC Field strength: A general term that means the magnitude of the electric field vector (in volts per meter) or the magnitude of the magnetic field vector (in ampere-turns per meter). As used in the field of EMC/EMI, the term field strength shall be applied only to measurements made in the far field and shall be abbreviated as FS. For measurements made in the near field, the term electric field strength (EFS) or magnetic field strength (MFS) shall be used, according to whether the resultant electric or magnetic field, respectively, is measured. Penetration: The passage through a partition or wall of an equipment or enclosure by a wire, cable, pipe, or other conductive object. Radio frequency interference (RFI): Synonymous with electromagnetic interference. Shielding effectiveness: A measure of the reduction or attenuation in the electromagnetic field strength at a point in space caused by the insertion of a shield between the source and that point. Signal reference subsystem: This subsystem provides the reference points for all signal grounding to control static charges, noise, and interference. It may consist of any one or a combination of the lower frequency network, higher frequency network, or hybrid signal reference network. TEMPEST: A code word (not an acronym) which encompasses the government/industrial program for controlling the emissions from systems processing classified data. Individual equipment may be TEMPESTed or commercial equipment may be placed in shielded enclosures. Related Topics 10.3 The Ideal Linear-Phase Low-Pass Filter • 10.4 Ideal Linear-Phase Bandpass Filters • 55.3 Dielectric Breakdown References AFSC Design Handbook, DH1-4, Electromagnetic Compatibility, 4th ed., U.S. Air Force, Wright-Patterson Air Force Base, Ohio, January 1991. R. F. Ficchi, Ed., Practical Design for Electromagnetic Compatibility, Hayden, 1971. E. R. Freeman, Electromagnetic Compatibility Design Guide for Avionics and Related Ground Support Equipment, Norwood, Mass.: Artech House, 1982. L. H. Hemming, Architectural Electromagnetic Shielding Handbook, New York: IEEE Press, 1991. B. Keiser, Principles of Electromagnetic Compatibility, 3rd ed., Norwood, Mass.: Artech House, 1987. Y.J. Lubkin, Filter Systems and Design: Electrical, Microwave, and Digital, Reading, Mass.: Addison-Wesley, 1970. MIL-HDBK-419A, Grounding, Bonding, and Shielding of Electronic Equipment and Facilities, U.S. Department of Defense, Washington, D.C., 1990. R. Morrison, Grounding and Shielding Techniques in Instrumentation, New York: John Wiley, 1986. R. Morrison and W. H. Lewis, Grounding and Shielding Techniques in Facilities, New York: John Wiley, 1990. T. Rikitake, Magnetic and Electromagnetic Shielding, Amsterdam: D. Reidel, 1987. N. O. N. Violetto, Electromagnetic Compatibility Handbook, New York: Van Nostrand Reinhold, 1987. D. R. J. White, Shielding Design, Methodology and Procedures, Springfield, Va.: Interference Control Technologies, 1986. D. R. J. White, A Handbook on Electromagnetic Shielding Materials and Performance, Springfield Va.: Interference Control Technologies, 1975. Further Information The annual publication Interference Technology Engineers’ Master (Item), published by R&B Enterprises, West Conshohocken, Pennsylvania, covers all aspects of EMI including an extensive product directory. The periodical IEEE Transactions on Electromagnetic Compatibility, which is published by The Institute of Electrical and Electronics Engineers, Inc., provides theory and practice in the EMI field. The periodical EMC Test & Design, published by the Cardiff Publishing Company, is a good source for practical EMI design information
o The periodical "emf-emi control"published bimonthly by EEC Press, Gainesville, VA, is an excellent source ractical emi information The periodical Compliance Engineering, published quarterly by Compliance Engineering, Inc, is a good source for information on EMC regulations and rules 40.2 Spectrum, Specifications, and Measurement Techniques Vichate Ungvichian and John M. roman Electromagnetic radiation is a form of energy at a particular frequency that can propagate through a medium. This intentionally or unintentionally generated electromagnetic energy is considered as electromagnetic inter- ference(EMI) if it degrades the performance of electronic systems. The purposeful generation of electromag- netic energy for communications can be defined as intentionally generated EMI; unintentionally generated EMI can be created, for example, by the electrical signals in a computer and may be radiated into space by way of the interconnecting cables and/or by openings in the device enclosures All electrical devices create some form of electromagnetic energy that may potentially interfere with the operation of other electrical devices outside the system(inter-system) or within the system(intra-system).Due to the increasing man-made eMi generated around the globe, allowable limits as well as measurement tech niques on RF noise/interference have been set at national and international levels. The Federal Communications Commission and the Military are the two governing bodies in the United States setting standards on EMI, whereas the International Electrotechnical Commission is the ruling body in Europe. These ruling bodies are concerned with only a fraction of the total electromagnetic spectrum Electromagnetic Spectrum The frequency spectrum of electromagnetic energy can span from dc to gamma ray(1021 Hz) and beyond Figure 40.13 shows the typical frequency spectrum chart over a fraction of hertz to 6 x 102 Hz The spectrum for use in electromagnetic compatibility(EMC) purposes covers only from a few hertz(extreme low frequency, ELF)to 40 GHz(microwave bands). ELF has been in use mostly in the area of biological research and ELF communications. On the other side of the spectrum, the electronic devices must function in a hostile environment, in military applications, over the gigahertz frequency range INFRA SONIC SONIC ULTRA SONIC itit盖ut !!!H!n RADIO RAkR一xmN說 iit i iiiiiit iiiii事 Liliiiil i iiitiit 画中m"m闻mrm=i ULTRA VIOLET 请浦;;;需等西避 FIGURE 40.13 The frequency spectrum chart( Contributed by Luther Monell, North America Rockwell Corp. c 2000 by CRC Press LLC
© 2000 by CRC Press LLC The periodical “emf-emi control” published bimonthly by EEC Press, Gainesville, VA, is an excellent source of practical EMI information. The periodical Compliance Engineering, published quarterly by Compliance Engineering, Inc., is a good source for information on EMC regulations and rules. 40.2 Spectrum, Specifications, and Measurement Techniques Vichate Ungvichian and John M. Roman Electromagnetic radiation is a form of energy at a particular frequency that can propagate through a medium. This intentionally or unintentionally generated electromagnetic energy is considered as electromagnetic interference (EMI) if it degrades the performance of electronic systems. The purposeful generation of electromagnetic energy for communications can be defined as intentionally generated EMI; unintentionally generated EMI can be created, for example, by the electrical signals in a computer and may be radiated into space by way of the interconnecting cables and/or by openings in the device enclosures. All electrical devices create some form of electromagnetic energy that may potentially interfere with the operation of other electrical devices outside the system (inter-system) or within the system (intra-system). Due to the increasing man-made EMI generated around the globe, allowable limits as well as measurement techniques on RF noise/interference have been set at national and international levels. The Federal Communications Commission and the Military are the two governing bodies in the United States setting standards on EMI, whereas the International Electrotechnical Commission is the ruling body in Europe. These ruling bodies are concerned with only a fraction of the total electromagnetic spectrum. Electromagnetic Spectrum The frequency spectrum of electromagnetic energy can span from dc to gamma ray (1021 Hz) and beyond. Figure 40.13 shows the typical frequency spectrum chart over a fraction of hertz to 6 ¥ 1022 Hz. The spectrum for use in electromagnetic compatibility (EMC) purposes covers only from a few hertz (extreme low frequency, ELF) to 40 GHz (microwave bands). ELF has been in use mostly in the area of biological research and ELF communications. On the other side of the spectrum, the electronic devices must function in a hostile environment, in military applications, over the gigahertz frequency range. FIGURE 40.13 The frequency spectrum chart. (Contributed by Luther Monell, North America Rockwell Corp.)