1、MIGHDBK-1195 - MILITARY HANDBOOK / /- , r RADIO FREQUENCY SHIELDED ENCLOSURES . AMSC NIA DISTRIBUTION STATEMENT A. APPROVED FOR PUBLIC RELEASE DISTRIBUTION IS UNLIMITED ,. AREA FACR T THIS DOCUMENT CONTAINS PAGES. , Provided by IHSNot for ResaleNo reproduction or networking permitted without license
2、 from IHS-,-,-MIL-HDBK-IIL FA 4977q70 0028L7b 5 i MIL-HDBK-1195 ii Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-3395 FA 9799970 0028377 7 W MIL-HDBK-1195 ABSTRACT Electromagnetic Interference (EMI) is a description of the phenomenon which
3、 results from allowing conducted and radiated electrical signals to reach destinations where their presence is undesirable. computer malfunction or error, detonation of electrically explosive devices, or be the cause for loss of classified information to an enemy. of this handbook is to provide a ba
4、sic understanding of the problems associated with the acquisition of a facility containing one or more EM1 shielded enclosures. It is intended that only the characteristics of the addressed. presents basic criteria of importance during the planning, design, and construction of a typical facility con
5、taining an EM1 shielded enclosure. Uncontrolled EM1 may cause The objective . facility that are unusual in comparison to a nonshielded facility will be This handbook is a brief introduction to EM1 shielding theory, and s I* iii Provided by IHSNot for ResaleNo reproduction or networking permitted wit
6、hout license from IHS-,-,-MIL-HDBK-1195 iv ,- i Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-e MIL-HDBK-1195 FA 7979770 0028179 0 MIL-HDBK-1195 FOREWORD This handbook has been developed from an evaluation of facilities in the shore establishment,
7、from surveys of the availability of new materials and construction methods, and from selection of the best design practices of the Naval Facilities Engineering Command (NAVFACENGCOM), other Government agencies, and the private sector. This handbook was prepared using, to the maximum extent feasible,
8、 national professional society, association, and institute standards. Deviations from this criteria, in the planning, engineering, design, and construction of naval shore facilities, cannot be made without prior approval of NAVFACENGCOMHQ Code 04. b Design cannot remain static any more than can the
9、functions it serves or the technologies it uses. Accordingly, recommendations for improvement are Facilities Engineering Command, Code 406.2, P.O. Box 727, San Bruno, CA 94066-0720; telephone (415) 877-7422. .-. encouraged and should be furnished to Commander, Western Division, Naval THIS HANDBOOK S
10、HALL NOT BE USED AS A REFERENCE DOCUMENT FOR PROCUREMENT OF FACILITIES CONSTRUCTION. IT IS TO BE USED IN THE PURCHASE OF FACILITIES ENGINEERING STUDIES AND DESIGN (FINAL PLANS, SPECIFICATIONS, AND COST ESTIMATES). DO NOT REFERENCE IT IN MILITARY OR FEDERAL SPECIFICATIONS OR OTmR PROCUREMENT DOCUMENT
11、S. V Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-3175 FA- 9799970 0028380 7 MIL-HDBK-1195 vi Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. Section 1 1.1 1.2 1.2.1 1.2.2 1.2.3 1.3 1.4
12、1.4.1 1.4.2 1.4.3 1-4.4 Section 2 2 :1 2.1.1 2.2 2.3 2.3.1 2.4 2.4.1 2.4.2 2.5 2.6 2.6.1 2.6.2 2.6.2.1 2.6.2.2 2.6.2.3 2.6.3 2.6.4 26.5 2.7 2.8 2.8.1 2.8.2 2.8.3 2.8.4 2.9 2.9.1 2.9.2 2.9.3 2.10 2.11 2.11.1 MIL-HDBK-1195 FA W 9999970 002B1L 7 W MIL-HDBK-1195 RADIO FREQUENCY SHIELDED ENCLOSURES CONTE
13、NTS Page INTRODUCTION Scope 1 Responsibilities . 1 Chief of Naval Operations 1 Maintenance Authority 2 Designer . 2 Policy . 3 Principal Data Sources . 3 Naval Shore Electronics Criteria Handbooks . 4 NAVFAC Design Manuals 4 Exceptions . 4 Base Electronic System Engineering Plan (BESEP) 3 BASIC ELEC
14、TROMAGNETIC INTERFERENCE SHIELDING THEORY Introduction . 5 Increased Need for Shielding . 5 Sources of EM1 . 5 Purposes for EM1 Shielding . 5 Shielding Effectiveness Level 6 Characteristics of EM1 Waves . 6 Antenna Emissions 7 Shielding Material characteristics . 8 Penetrations . 10 Waveguide Below
15、Cutoff Penetration Theory 10 Door Penetrations 11 Effect of Construction on Door Shielding . 12 Considerations for Door Replacement 14 Duct Penetrations 14 Piping and Conduit Penetrations 16 Structural Penetrations 21 Conducted EM1 Isolation 21 EM1 Filters for Electrical Conductors 25 EM1 Filters fo
16、r Electrical Power . 25 EM1 Filters for Signal Circuits 27 Shielding Effectiveness Equation . 7 Door Closure/Seal Comparisons 14 Electrical Filter Design Specification Requirements 27 Insertion Loss Measurements of Electrical Filters 29 Facility Grounding System 30 Lightning Protection Subsystem . 3
17、0 Fault Protection Subsystem . 30 Signal Reference Ground Subsystem TEMPEST Shielding Requirements . 33 Types of Shielding Systems . 33 Bolted, Modular Shielded Enclosures 31 36 vi i Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-U 2.11.2 2 0 11 02
18、0 2 Ill 02.2 2.12 2.12.1 2.13 Section 3 3.1 3.1.2 3.2 3.2.1 3.2.2 3.1.1 3.203 3,204 3.2.5 502.6 3.3 3*4 3 e5 3a5.1 3.5.2 Section 4 4.1 4.2 4.3 403.1 4.3.2 4.3.3 443.4 4.4 4.5 4.5. 1 4*5ol*l 4.6 4.7 4.701 4.8 4.9 4.901 4.902 4.9.3 4.10 4.51 Welded Shielded Enclosures . Large Welded Structures Warping
19、 Due to Welding . EM1 Conductive Gaskets. Cements and Tapes Mesh Gaskets Fingerstrips . PLANNING PHASE Introduction Construction Requirements . EMC Surveys and Studies . Types of Shielded Enclosures TEMPEST High Altitude Electromagnetic Pulse (HEMP) Hazards of Electromagnetic Radiation to Personnel
20、(HERP) Hazards of Electromagnetic Radiation to Ordnance (HERO) Hazards of Electromagnetic Radiation to Fuel (HERF) Shielding for Communication-Electronics (C-E) Facilities . Electromagnetic Compatibility (EMC) Evaluation . Base Electronic System Engineering Plan (BESEP) Types of Construction for EM1
21、 Shielding Demountable Enclosures . Welded Enclosures DESIGN PHASE Introduction . Predesign Architectural Design . Comparison of Various Seals Vestibule/Threshold Protection . Size and Location of Power Filters . Shielding of Access Penetrations . Structural Design Mechanical Design Minimizing and S
22、hielding Mechanical Penetration Dimensions and Materials for Shielding Mechanical Penetrations . Fire Protection Design Electrical Design Considerations Design Allocations or Power Filters Specification Design Considerations . Testing . Shielding Effectiveness Leak Detection System (SELDS) Testing A
23、fter Shielding Completion . Testing Before Finish is Installed . Cost Considerations Design Review viii 36 46 46 46 50 50 52 52 52 52 52 53 53 53 53 53 53 54 54 54 55 56 56 56 56 57 57 57 57 58 58 58 58 59 59 59 60 60 61 62 62 62 O 1 U a Provided by IHSNot for ResaleNo reproduction or networking per
24、mitted without license from IHS-,-,-. MIL-HDBK-1195 FA a 979777O 0028143 I?. MIL-HDBK-1195 Page 4.11.1 Review of Drawings . 63 Section 5 CONSTRUCTION PHASE 5.1 Introduction . 64 5.2 Submittals . 64 5.2.1 EM1 Test Module 64 5.2.2 Supervision of Construction 65 5.3 Installation . 65 * 5.3.1 Panels . 6
25、5 5.3.1.1 Weather Protection During Construction . 65 5.3.1.2 Requirements for Clean and Tight Seams . 65 5.3.2 Penetrations . 66 5.3.3 Doors 66 5.3.3.1 Doorframe Contact Surfaces . 66 5.3.4 Waveguide-type Air Vents . 66 5.3.5 RFI filters 67 5.3.6 Grounding 67 5.4 Testing 67 5.4.1 Leak Detection Sys
26、tems . 67 5.3.1.3 Foundations and Ceilings . 66 J Bibliography 68 References 69 Acronyms 71 Glossary 73 a LIST OF FIGURES Figure Pane 1 RF Door and Wall Seam Type Cross-sections 13 2 Preferred Waveguide Air Vent Filter, Bolted and Welded Enclosures 15 3 Typical TEMPEST Pipe Penetration. Bolted and W
27、elded Enclosures . 17 4 Single Skin Bolted Enclosure Penetration Panel . 18 5 Waveguide Fluid Attenuator Insert. TEMPEST Piping Penetrations . 19 6 RF Bolted Floor Drain Penetration With Attenuator Insert . 20 7 RF Shielding of Interior Steel Column Penetration 22 8 RF Shielding, Interior Reinforced
28、 Concrete Column Penetration 23 9 RF Shielding, Exterior Concrete Column . 24 10 TEMPEST Required Filter Insertion Loss . 26 Matched Source and Load Impedances . 28 Equipotential Plane 32 11 12 TEMPEST Signal Filter Attenuation Requirements, Measured With High Frequency Grounding. Using Raised Floor
29、ing as an ix e - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-IL FA W 9499970 OOi 2. recommended locations of electronic equipment, power panelboards, special red or black panelboard designations, and special power requirements; 3. identi
30、fication of red areas; 4. antenna locations and the number, type, performance, and frequency ranges required; 5. cable types and termination locations; 6. radio-frequency (RF) shielding requirements, other requirements for precautions against radiation hazards, and characteristics of the source of r
31、adiation; 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-2275 FA 779797 2818I3 i MIL-HDBK-1195 7. electronic equipment areas of concentrated heat load and requirements for special air conditioning or environmental control; 8. recommended
32、locations of compressed air outlets, specifying pressure and valve requirements; 9, grounding systems; 10. and internai security. Requirements relevant to the specific site and supporting facilities are also included. furnished to the designer depend on the circumstances of the project, and in emerg
33、encies, may be brief and subject to augmentation as the project progresses, The completeness of such information and the amount of detail 1,4,2 Naval Shore Electronics Criteria Handbooks. These handbooks will aid the NAVFAC design agent in understanding the mission of the facility. The series provid
34、es background information and planning and technical criteria for design of electronic facilities. All referenced volumes included in the series are listed in references, The first six volumes address major considerations or selecting, designing, installing, and supporting general electronic facilit
35、y systems, The subsequent volumes address specific kinds of systems . 1.403 NAVFAC Desian Criteria. The design criteria series presents criteria for the design of facilities under the cognizance of the Naval Facilities Engineering Command. handbook are listed in references. The NAVFAC design criteri
36、a referenced in this 1,404 Excer! 3 MIL-HDBK-1195 SE = 10 10g(E,/Zi)/(E2/22) dB SE = 10 10g(H12/Z1)/(H22/Z2) dB Pl = EI2/Z1 = Hi2 Zl P2 = EZ2/Z2 = HZ2 22 El = Incident Electric Field E, = Transmitted Electric Field Hl = Incident Magnetic Field H2 = Transmitted Electric Field When the wave impedance
37、Z of the incident and transmitted electromagnetic field is the same with and without the shielding in place the expression for SE reduces to its familiar form: EQUATIONS: SE = 20 log (E,/E2) dB 2.5 Shielding Material Characteristics. When an electromagnetic wave encounters an enclosing conductive ma
38、terial shield, the portion of the wave transmitted beyond the shielding barrier is reduced in magnitude by both reflection and absorption by the shielding material. The reflection loss occurs at the two interfaces between the transmitting medium (typically air) and the shielding material (typically
39、a conducting metal such as sheet steel, copper, or aluminum), The absorption takes place as the wave passes through the conductive material. The absorption loss in the wave energy results from dissipated heat loss by currents induced in the conductive material by the electric and magnetic fields of
40、the wave passing through. occurs because of the mismatch in wave impedance between the propagating medium and the conductive material. effectiveness of a conductive material is typically expressed as follows: The reflection loss The relationship or shielding EQUATION : SE = R + A f CI dB (7) where R
41、 = reflection loss A E: absorption loss C = correction term for re-reflection within the metal surfaces The correction term (C) is usually of small magnitude and ignored when the absorption loss (A) is greater than about 10 dB. The reflection loss (Rp) for plane waves impinging on shielding material
42、 is: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-3375 FA 7779770 0028373 5 E QUAT1 ON : where MIL-HDBK-1195 Rp = Reflection loss for plane waves pr = Permeability relative to copper gr = Conductivity relative to copper f = frequency in H
43、z The reflection loss (Rm) for the magnetic loop measurements in the near field is: o EQUATION: Rm = 20 log ( .0117/rfgr/pr0*5)+(5.35 r fgr/r*)+.354dB (9) where r = Distance from source to shield in meters The reflection loss (RE) for the electric dipole measurements in the near field is: EQUATION :
44、 RE = 322-10 log (prf3r2/gr)I The absorption loss (A) is a simpler relationship, not dependent on the antenna used, but directly proportional to material thickness (d) in meters. EQUATION : where d = Thickness of shield material in meters For metal foil shields at low frequencies where the absorptio
45、n loss (A) is minimal, (less than about 10 dB), the correction factor for re-reflections within the shield (C) must be considered. The correction factor (C) is: EQUATION: C = 20 log l - r 10-A(cos0.23Al - j sin 0.23Al)I dB where I r = Reflection coefficient A = Absorption loss Here (A) is the shield
46、 absorption loss, and () is the dimensionless two-boundary reflection coefficient. coefficients are identified as follows: In the foregoing equations the various 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-1195 where pr = relative perm
47、eability of the shielding material with respect to that of free space. yo = permeability of free space, equal to 4a xlO-7 henries per meter, gr = relative conductivity of the shielding material with respect to that of copper. W v) O k I- a t; W W a. Y c( n n W e 3 v) O -1 u W W O I n 5 3 t; El d ti
48、m w v) I- W O Figure 3 Typical TEMPST Pipe penetration, Bolted and Welded Enclosure 17 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-LLSi FA p 9999970 ORiiOi i MIL-HDBK-1195 WE D CO STEEL SKIN 6-INCH DIELECTRIC ISOLATION - STANDARD BRASS OR STEEL PIPE NIPPLE I OUTSIDE ENCLOSURE INSIDE ENCLOSURE SECTION A-A PENETRATION PLATE AND FRAME Figure 4 Single Skin Bolted Enclosure Penetration Panel 18 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-
