Engineering Design Handbook - Electromagnetic Compatibility: (DARCOM-P 706-410)

255 Pages·14.817 MB·English

DARCOM PAMPHLET DARCOM-P 706-410
ENGINEERING DESIGN
HANDBOOK
ELECTROMAGNETIC
COMPATIBILITY
HQ, USA MATERIEL DEVELOPMENT AND READINESS COMMAND MARCH 1977
DARCOM PAMPHLET DARCOM-P 706-410
DARCOM-P 706410
LIST OF ILLUSTRATIONS
Figure No . Title Page
1-1 Forms of Interference Coupling ...................................................... 1-1
1-2 Communication System and Its Environment ......................................... 1-2
2- 1 Estimates of Median Values of Man-Made Noise Expected at Typical Locations ........ 2-2
2-2 Model of System and Its Environment ................................................ 2-3
2-3 Field Strength as a Function of Distance of Transmitter ................................ 2-4
2-4 Typical EMC Functional Interfaces ................................................... 2-25
2-5 Authority and Processing of RF Spectrum Applications ................................ 2-27
2-6 Cost-Effectiveness Model for Selecting a Configuration ................................ 2-29
2-7 EMC Decision Process ............................................................... 2-30
2-8 Flow Chart - EMC Decisions/Actions in the LCSMM for Major Systems ............. 2-31
2-9 Flow Chart - EMC Decisions/Actions in the LCSMM for Nonmajor Systems ......... 2-32
B- 1 Sample Frequency Matrix ............................................................ B-3
3- 1 Noise Source Equivalent Circuits of a Resistor ........................................ 3-5
3-2 Amplitude Probability Distribution of the Noise Envelope ............................. 3-8
3-3 Conversion of Vd in One Bandwidth to Vd in Another Bandwidth ...................... 3-9
3-4 Noise Variability (Summer: OOOO-0400 h) .............................................. 3-10
3-5 Expected Values of Atmospheric Radio Noise Fa,,,. dB Above kT, b at 1 MHz ........... 3-11
3-6 Variation of Radio Noise With Frequency ............................................ 3-12
3-7 Waveform of Effective Radiated Electric Field ........................................ 3-13
3-8 Lightning Stroke. Complete Discharge Current ........................................ 3-13
3-9 Cumulative Distribution of the Number of Current Peaks in an Individual
Lightning Discharge ................................................................ 3-14
3-10 Probability Density of the Time Between Pulses of the Atmospheric
Noise Envelope ..................................................................... 3-14
3-1 1 Increment of Solid Angle Measured at the Observer’s Position .......................... 3-15
3-12 Brightness Temperature Distributions. Frequency 3 GHz .............................. 3-16
3-13 Antenna Temperatures Due to Oxygen and Water Vapor
(Standard Summer Atmosphere) .................................................... 3-17
3-14 Basic Parts of CW Transmitter ....................................................... 3-23
3-15 Typical Transmitter Output Spectra .................................................. 3-23
3-16 Typical Conducted Narrowband Emissions ........................................... 3-24
3-17 Typical Narrowband Electric Field Levels ............................................. 3-25
3-18 Simplified Switching Circuit .......................................................... 3-26
3-19 A Unit Step at t = t, ................................................................. 3-27
3-20 Interference Level for a 1.V. I-ps Trapezoidal Pulse and I-V Unit Step
(0.1 ps rise time) .................................................................... 3-27
3-2 1 Contact Arc Suppression ............................................................. 3-28
3-22 Typical Switching Transients ......................................................... 3-29
3-23 Make Contact Conducted EM1 Associated With Current Magnitudes in an
Electromagnetic Relay Contact Circuit .............................................. 3-30
3-24 Break Contact Conducted EM1 Associated With Current Magnitudes in an
Electromagnetic Relay Contact Circuit .............................................. 3-31
3-25 EM1 Radiated from a Conventional Electromagnetic Relay Coil ....................... 3-32
3-26 Conducted Noise Voltage from a 0.5-kW dc Generator at Full Load ................ 3-34
3-27 Resistive and Reactive Components of EM1 Source Impedance of 0.5-kW dc
Generator Showing Variation With dc Load Current ................................. 3-35
3-28 Dynamotor (14 V dc-250 V dc) Conducted EM1 Voltage Line to Ground ................ 3-36
3-29 EM1 Source Voltage of Fluorescent Lamp ............................................. 3-37
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DARCOM-P 706-410
LIST OF ILLUSTRATIONS (cont’d)
Figure No. Title Page
3-30 Source Impedance of the Fluorescent Lamp Fixture ................................... 3-38
3-3 1 Broadband Radiated Interference (Peak) .............................................. 3-39
3-32 Spark Current Generation and Current Spectra ........................................ 3-40
3-33 Individual Vehicle Electromagnetic Radiations ........................................ 3-41
3-34 Average Probability Distributions for Freeway Traffic. 24.1 1 MHz ..................... 3-42
3-35 Oscillograms of Reverse Current Transients for IN435 Diode at 880-mA dc Load ....... 3-43
3-36 Radiated EM1 from High-voltage Power Lines ........................................ 3-44
3-37 Waveforms Resulting from Switch-type Nonlinearities ................................. 3-49
3-38 Waveforms Resulting from Saturating Nonlinearities .................................. 3-45
3-39 Ideal Half- and Full-wave Rectifiers .................................................. 3-46
3-40 Generation of Harmonics in Magnetic Materials ...................................... 3-47
3-4 1 Plot. on a Spectrum Level Basis. of (I) the Speech Area for a Man Talking in a
Raised Voice; (2) the Region of “Overload” of the Ear of an Average Male
Listener; and (3) the Threshold of Audibility for Young Ears .......................... 3-49
3-42 Several Experimental Relations Between Articulation Index and Speech
Intelligibility ....................................................................... 3-50
3-43 Relation Between Signal-to-Noise Ratio and Mean Opinion on a 6-point Scale .......... 3-51
3-44 Interference Conditions on PPI Display ............................................... 3-53
3-45 Search Radar Detection Range vs Interference Level ................................... 3-54
3-46 Binary Error Probability vs CNR - Coherent Detection ............................... 3-55
3-47 Error Rates for Several Binary Systems ............................................... 3-57
3-48 Block Diagram of Basic Receiver Elements ............................................ 3-61
3-49 Interference Produced by a Signal in an Adjacent Channel ............................. 3-61
3-50 Unwanted Signal Spectrum and the Receiver Bandpass Characteristic .................. 3-63
3-5 1 Possible Spurious Responses in a High-frequency Receiver With Local Oscillator
Frequencyf, Set 30 MHz Below Desired Frequency ................................... 3-68
3-52 Relative Signal-to-Interference Response for Equal Outputs ............................ 3-68
3-53 Waveform Diagram for Desensitization Signals ....................................... 3-72
.............................................
3-54 Spectra of Undesired and Desired Signals 3-72
................................................................
3-55 Desensitization Curve 3-73
...................................
3-56 Tests Results of Conversion Loss in a Crystal Mixer 3-74
.........................................................
3-57 Mutual Conductive Coupling 3-75
.........................................................
3-58 Mutual Inductance Coupling 3-76
........................................................
3-59 Mutual Capacitance Coupling 3-76
..............................................
3-60 Coordinate System for Magnetic Source 3-78
3-61 Magnetic Field Strength from Circular Current Loop on Axis and in Plane
............................................................................
ofLoop 3-79
3-62 Normalized Magnetic Field Intensity from Circular Current Loop on Axis and in
......................................................................
Plane of Loop 3-80
.........................................
3-63 Maximum Flux Density from a Circular Loop 3-81
.......................................
3-64 Magnetic Field Strength of 500-W Transformer 3-82
........................................................
3-65 Dipole Strength vs Frequency 3-83
...............................................
3-66 Flux Density from Parallel Conductors 3-86
3-67 Spacing of Conductors in the Equivalent Two-wire Line as a Function of
Frequency for Different Cables ...................................................... 3-87
3-68 Correction Factor for Estimating Field from Twisted Wire Pair ........................ 3-88
3-69 Coaxial Cable Geometry and Parameters .............................................. 3-89
3-70 Plot Showing Frequency Dependence of Normalized Surface Transfer Impedance
for Solid Shields .................................................................... 3-90
3-7 1 Surface Transfer Impedance .......................................................... 3-91
3-72 Dimensional Notation for Braided Shield ............................................. 3-92
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DARCOM-P 706410
LIST OF ILLUSTRATIONS (cont’d)
Figure No . Title Page
3-73 Surface Transfer Impedance of RG-58 C/U Cable ..................................... 3-93
3-74 Surface Transfer Impedance of RG 223/U. Formerly RG.55/U. Cable ................. 3-94
3-75 Surface Transfer Impedance of RG-2 13/U. Formerly RG.8A/U. Cable ................ 3-95
3-76 Transfer Impedance vs Frequency. RG.62B/U. Formerly RG-I 3A/U .................. 3-96
3-77 Transfer Impedance vs Frequency. RG-216/U ........................................ 3-96
3-78 Transfer Impedance vs Frequency. RG-58 A/U Triax .................................. 3-97
3-79 Transfer Impedance vs Frequency. RG- I2/U Armored (armor floating) ................ 3-97
3-80 Transfer Impedance vs Frequency. RG 12/U Armored (armor bonded to cable
shield at ends) ...................................................................... 3-98
3-8 1 Patterns for Field from Leakage Currents ............................................. 3-98
3-82 Cable and Loop Susceptibility ........................................................ 3-99
3-83 Model for Electric Coupling .......................................................... 3-100
3-84 Frequency Dependence of Voltage Ratio for Electric Coupling ......................... 3-100
3-85 Circuit and Equations Representing Electric Coupling and Magnetic Coupling
Between Parallel Lines .............................................................. 3-101
3-86 Approximate Signal Coupling in Wiring .............................................. 3-102
3-87 Free Space Transmission ............................................................. 3-105
3-88 Values of R and cp as Functions of tan$ ............................................... 3-106
3-89 Transmission Loss Over Plane Earth .................................................. 3-108
3-90 Minimum Effective Antenna Height .................................................. 3-109
3-9 1 Diffraction Loss Around a Perfect Sphere ............................................. 3-1 11
3-92 Diffraction Loss Relative to Free Space Transmission at All Locations Beyond
Line-of-sight Over a Smooth Sphere ................................................. 3-1 12
3-93 Knife-edge Diffraction Loss Relative to Free Space .................................... 3-1 13
......................................................
3-94 Transmission Loss vs Clearance 3-1 14
3-95 Field Intensity for Vertical Polarization Over Sea Water for 1 kW-Radiated Power
...............
from a Grounded Whip Antenna as a Function of Roughness of Terrain 3-1 15
3-96 Field Intensity for Vertical Polarization Over Poor Soil for I-kW Radiated Power
....................................................
from a Grounded Whip Antenna 3-1 17
3-97 Field Intensity for Vertical Polarization Over Sea Water for I-kW Radiated
..............................................
Power from a Grounded Whip Antenna 3-1 17
3-98 Antenna Height Gain Factor for Vertical Polarization Over Poor Soil .................. 3-1 18
..................
3-99 Antenna Height Gain Factor for Vertical Polarization Over Sea Water 3-1 18
3-100 Power Line Conducted Interference Model ............................................ 3-1 19
3-101 Model of Interference Source and Its Load ............................................ 3-1 19
3-102 Two-terminal Representation ........................................................ 3- 120
3-103 Impedance Between Live and Earth Connections at Ring Main Sockets in
...................................................................
ERA Laboratory 3-122
3-104 Gamma Probability Density for Several Parameter Values ............................. 3-123
3- 105 Comparison of Uniform and Gaussian Probability Density Functions With Same
.......................................................
Mean and Standard Deviation 3-123
3- 106 Distribution of VL/tM5. - to 30-MHz Typical Power Lines ............................. 3-125
3- 107 Distribution of VL/tMT. ypical Power Line ........................................... 3-126
3-108 Distribution of VL/tM5 0.. 100.. and 200-kHz Typical Power Lines ..................... 3- 127
3-109 Common-mode Model ............................................................... 3- 128
3-1 10 Common-mode Impedance of Receiver Bonded to Ground Plane ....................... 3-129
3-1 11 Common-mode Impedance of Receiver Grounded by Means of 3-ft Coaxial
Antenna Cables .................................................................... 3- 1 30
3-1 12 Phase Angle of Common-mode Impedance of Receiver Connected as for
Fig.3-111 .......................................................................... 3-131
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DARCOM-P 706-410
LIST OF ILLUSTRATIONS (cont’d)
Figure No. Title Page
3-1 13 Impedance Magnitude and Phase vs Frequency; BS.348. Common Mode Grounded
Shielded Enclosure Test Bench ...................................................... 3-132
3-1 14 Impedance Magnitude and Phase vs Frequency; Common-mode -
Receiver Ungrounded ............................................................... 3- 133
3-115 Floating Ground Plane ............................................................... 3- i34
3-1 16 Single-point Ground System .......................................................... 3-1 34
3-1 17 Multipoint Ground System ........................................................... 3- 134
3-1 I8 Multipoint Ground Detail ............................................................ 3-1 35
3-1 I9 Balanced Coupling Circuit ........................................................... 3- 135
4- 1 Interference Levels for Eight Common Pulses ......................................... 4-3
4-2 Feedback Network .................................................................. 4-5
4-3 Feedback Around Modulator ........................................................ 4-5
4-4 Predistortion Block Diagram ......................................................... 4-6
4-5 Circuits for Controlling Common-mode Currents ..................................... 4-7
4-6 Output Stage Decoupling ............................................................ 4-8
4-7 Tuned Output Stage Decoupling ...................................................... 4-9
4-8 Emitter-Follower Decoupling ........................................................ 4-9
4-9 Interstage Decoupling ................................................................ 4-10
4-10 Typical Final Power Supply Configuration ............................................ 4-10
4-1 1 Mutual Inductance Between Two Wires Over a Ground Plane .......................... 4-11
4-12 Capacity per Inch of Two-wire Line With Various Wire Diameters as a Function of
Spacing ............................................................................ 4-11
4-13 Inductance of a Wire Over a Ground Plane ............................................ 4-14
4-14 AC Inductive and Shield Attenuation Factors ......................................... 4-15
4-15 Transient Inductive and Shield Attenuation Factors ................................... 4-16
4-16 Shield Termination for Connectors ................................................... 4-19
4-17 Triaxial Cable Application ........................................................... 4-20
4-18 Continuous Equipment Enclosure Shield .............................................. 4-21
4-19 Incorrect Method of Introducing Shielded Cable ....................................... 4-22
4-20 Correct Method of Introducing Shielded Cable ........................................ 4-22
4-2 1 Connector With Shielding Shell Enclosure for Connecting Points ....................... 4-22
4-22 Connector Backshell Arrangement for Terminating Cable Shields ...................... 4-23
4-23 Backshell Arrangement for Terminating Cable Shields ................................. 4-24
4-24 Cable Shield Bonding ................................................................. 4-24
4-25 Poor Cable Bonding ................................................................. 4-25
4-26 Typical Cable Methods .............................................................. 4-26
4-27 Linear Two Port Model of Filter ...................................................... 4-27
4-28 Filter Attenuation as a Function of Frequency ......................................... 4-28
4-29 Capacitor Low-pass Filter ............................................................ 4-29
4-30 Metalized Capacitor Equivalent Circuit ............................................... 4-29
4-3 1 Insertion Loss of a 0.05-pF Aluminum Foil Capacitor ................................. 4-30
4-32 Three-terminal Capacitor ............................................................ 4-30
4-33 Typical Feedthrough Capacitor Construction ......................................... 4-31
4-34 Inductor Low-pass Filter ............................................................. 4-31
4-35 Low-pass L-Section Filter ............................................................ 4-32
4-36 Response Modes of Filters ........................................................... 4-33
4-31 Low-pass n-Filter .................................................................... 4-33
4-38 Low-pass T-Filter ..................................................................... 4-33
4-39 Insertion Loss for Mismatched Filters ................................................. 4-35
4-40 Insertion Loss of a Ferrite Tube Low-pass EM1 Filter .................................. 4-36
4-4 1 Typical Low-pass Filter Loss Characteristics. Low-pass Filter Only ..................... 4-36
xxii
DARCOM-P 706-410
LIST OF ILLUSTRATIONS (cont’d)
Figure No. Title Page
4-42 Typical Low-pass Filter Plus Lossy Filter Section ...................................... 4-36
4-43 Typical Characteristics of Lossy Connector ........................................... 4-37
4-44 Typical Characteristics of Lossy Line Suppressant Tubing .............................. 4-38
4-45 Low-pass to High-pass Transformation ............................................... 4-39
4-46 Example of Bandpass Filter Design ................................................... 4-40
4-47 Band-reject Filter Configurations ..................................................... 4-41
4-48 Twin-T Notch Filter ................................................................. 4-41
4-49 Twin-T Network With K = 1 ......................................................... 4-41
4-50 Twin-T Network with K = 0.5 ........................................................ 4-41
4-5 1 Twin-T Network With K = 2 ......................................................... 4-42
4-52 Active Filter for Power Line Interference .............................................. 4-43
4-53 Strip Transmission Line Construction ................................................. 4-44
4-54 Shorted Shunt Line Construction ..................................................... 4-45
4-55 Symmetrical T-Section Filter and Equivalent Network ................................. 4-45
4-56 Low-pass Filter and Equivalent Network .............................................. 4-46
4-57 Linear Taper Matching of Strip Lines ................................................. 4-46
4-58 Waffle-iron Waveguide Filter ......................................................... 4-46
4-59 Characteristics of Waffle-iron Waveguide Filter ....................................... 4-47
4-60 Septum Section ...................................................................... 4-48
4-6 I Rod and Bullet Septa ................................................................ 4-48
4-62 Tuned Cavity Section ................................................................ 4-48
4-63 Narrow Wall Mode Absorber Strips .................................................. 4-48
4-64 Effect of a Poor RF Ground Bond on Filter Effectiveness .............................. 4-49
4-65 Typical Filter Mounting Techniques .................................................. 4-49
4-66 Filter Installation .................................................................... 4-49
4-61 Incorrect Filter Mounting Methods ................................................... 4-50
4-68 Installation of Power Line Filters ..................................................... 4-50
4-69 Metal Shielding Effectiveness ......................................................... 4-51
4-70 Reflection Loss for Low-impedance Source ........................................... 4-53
4-7 1 Reflection Loss to a Plane-wave ...................................................... 4-54
4-72 Reflection Loss for High-impedance Source ........................................... 4-55
4-73 Absorption-loss Curve ............................................................... 4-56
4-14 Correction Factor in Correction Term for Internal Reflections ......................... 4-58
4-75 Absorption Loss A .................................................................. 4-59
4-76 Magnetic Field Reflection Loss R, ................................................... 4-60
4-77 Electric Field Reflection Loss RE ..................................................... 4-61
4-78 Plane Wave Reflection Loss Rp ....................................................... 4-62
4-79 Chart for Computing K for Magnetic Field Secondary Reflection Loss .............. 4-63
4-80 Chart for Computing Secondary Losses for Magnetic Fields ............................ 4-64
4-8 1 Shielding Effectiveness in Electric. Magnetic. and Plane Wave Fields of Solid
.
Copper and Iron Shields (for Signal Source 12 in from Shield at 100 Hz to
10GHz) ............................................................................ 4-67
4-82 Absorption Loss for Copper and Iron. dB per mil ...................................... 4-68
4-83 Shielding Effectiveness in Electric. Magnetic. and Plane Wave Fields of Copper
Shield (7-mil Thickness) for Signal Sources 165 ft from the Shield ...................... 4-70
4-84 Shielding Effectiveness in Electric. Magnetic. and Plane Wave Fields of Steel Shield
(1-mil Thickness) for Signal Sources 165 ft from the Shield) ........................... 4-71
4-85 Shielding Effectiveness in Electric. Magnetic. and Plane Wave Fields of Steel Shield
(50-mil Thickness) for Signal Sources 165 ft from the Shield ........................... 4-72
4-86 Total Reflection Loss at Both Surfaces of a Solid Steel Shield ........................... 4-76
4-87 Total Reflection Loss at Both Surfaces of a Solid Copper Shield ........................ 4-77
xxiii
DARCOM-P 706410
LIST OF ILLUSTRATIONS (cont’d)
Figure No . Title Page
4-88 Absorption Loss for Steel and Copper Shields at 30 Hz to 10. OOO MHz .................. 4-79
4-89 Multiple Shielding Applications ...................................................... 4-82
4-90 Currents Induced on Perforated Metal Sheet .......................................... 4-82
4-9 1 Typical Welded Screen Installation Over a Ventilation Aperture ........................ 4-83
4-92 Typical Clamped Screen Installation Over a Ventilation Aperture ...................... 4-83
4-93 Shielding Effectiveness of Various Copper Screens ..................................... 4-84
4-94 Shielding Effectiveness of Various Galvanized Steel Screens ............................ 4-85
4-95 Comparison of the Shielding Effectiveness of Single and Double 18 Mesh Copper
Screening .......................................................................... 4-86
4-96 Comparison of the Shielding Effectiveness of Single and Double 40 Mesh Copper
Screening .......................................................................... 4-87
4-97 Comparison of the Shielding Effectiveness of Single and Double 69 Mesh Copper
Screening .......................................................................... 4-88
4-98 Comparison of the Shielding Effectiveness of Single and Double 8 Mesh Galvanized
Steel Screening ..................................................................... 4-89
4-99 Attenuation vs Frequency Curves for Various Screens ................................. 4-91
4-100 Attenuation vs Frequency Curves for Various Screens and Honeycomb ................. 4-92
4-101 Minimum Shielding Effectiveness of Copper and Bronze Screening in a Magnetic
Field ............................................................................... 4-93
4- 102 Minimum Shielding Effectiveness of Steel Screening in a Magnetic Field ................ 4-94
4- 103 Honeycomb Type Ventilation Panel .................................................. 4-95
4- 104 Air Impedance of Perforated Metal and Honeycomb ................................... 4-95
4- 105 Air Impedance of Copper and Nickel Mesh ........................................... 4-95
4- 106 Attenuation - Rectangular Waveguide ............................................... 4-96
4- 107 Attenuation - Circular Waveguide ................................................... 4-97
4- 108 Shaft Arrangements .................................................................. 4-97
4-109 Seam Design for Minimum Interference ............................................... 4-99
4-1 10 Vertical Expansion Joint. an Example of a Complex Seam .............................. 4-100
4-1 11 Improper Gasket Application ......................................................... 4-101
4-1 12 Recommended Screw Spacing To Cause a Minimum of Buckling of the Metal ........... 4-102
4-1 13 Flat-flange Type Joint With Groove Gasket ........................................... 4-103
-
4-1 14 Typical Conductive Gasket Applications Flat Plate and Ridged Plate
Configurations ..................................................................... 4-103
4-1 15 Typical Conductive Gasket Applications .............................................. 4- 103
4-1 16 Types of “Flat” Gaskets ............................................................. 4-104
4-1 17 Typical Gasket Mounting Methods ................................................... 4-104
4-1 18 Sample Gaskets in Simulated Joints ................................................... 4-104
4-1 19 Insertion Loss vs Pressure for Resilient Metal Gasket .................................. 4-105
4- 120 Technique for Measurement of Insertion Loss of Resilient Metal Gasket ................ 4-106
4-121 Metal-to-Metal Contact Techniques of Cover and Case for Interference Shields ......... 4-108
4- 122 Typical Conductive Gasketing Application ............................................ 4- 1 10
4- 123 Combination Pressure and Interference Seals .......................................... 4-1 10
4- 124 Raintight Conductive Gasket Seal .................................................... 4-1 10
4-125 Comparison of Shielding Effectiveness vs Frequency for the Various 1/ 32.in . Thick
Shield Cans ........................................................................ 4- 1 1 2
4- 126 Typical Curves Showing Effects of Magnetic Saturation on Permeability of
Various Materials .................................................................. 4- 1 13
4- 12 7 Effect of Joint Orientation on Flux Paths .............................................. 4-1 14
4-128 Shield Economies .................................................................... 4-1 14
4- 1 29 Meter Shielding and Isolation ........................................................ 4-1 15
4- 130 Treatment of Cathode-ray Tube Openings ............................................. 4-1 17
xxiv
DARCOM-P 706.410
LIST OF ILLUSTRATIONS (cont’d)
Figure No . Title Page
4-131 Shielding Cable With Four Bands of Foil .............................................. 4-1 i8
4-132 Typical Conductive Caulking Applications ............................................ 4- 1 19
4- 133 Ground Lug Connection and Equivalent Circuit ....................................... 4-120
4-134 Grounding Methods ................................................................. 4- 12 1
4- 135 Typical Ground Potential Graph at a Specific Frequency ............................... 4-122
4- 136 Example of Intercircuit Coupling ..................................................... 4-1 22
4- 137 Effect of Circulating Currents on a Typical Circuit ..................................... 4-122
4- 138 Isolation Transformer Technique for Minimizing Ground Potential .................... 4- 123
4- 1 39 Single-point Ground Bus Arrangement ............................................... 4- 123
4-140 Direct Use of Chassis for Good Ground ............................................... 4-123
4-141 Variation of Soil Resistance With Temperature ........................................ 4-126
4- 142 Bonding Strap Impedance Characteristics ............................................. 4-1 28
4-143 Skin Depth in Copper, and Resistance and Reactance Variation With Frequency
for Conductors of Circular Cross Section ............................................ 4- 129
4- 144 Inductive Reactances of Bond Strap and a Bond Jumper Having Constant Cross-
Sectional Area ...................................................................... 4- 130
4- 145 Recommended Bond Strap Bolting Installation ........................................ 4- 1 3 1
4-146 Fault Current vs Maximum Allowed Resistance for Bonding Between Equipment
and Structure ....................................................................... 4- 1 3 1
4- 147 Typical Shock Mount Bond .......................................................... 4-1 33
4-148 Bonded Engine Shock Mount - Front ................................................ 4-134
4-149 Bonded Engine Shock Mount - Rear ................................................ 4-1 34
4- 1 50 Cable and Conduit Bonding .......................................................... 4-1 34
4-151 Bonding of Hinges ................................................................... 4-1 35
4-1 52 Cable Tray Section Bonding .......................................................... 4-1 35
4-153 Equipment Cabinets Bonded to Cable Tray ........................................... 4-1 35
5- 1 Installation of By-pass Capacitors .................................................... 5-4
5-2 Commutation of an Armature Coil by Laminated Brushes ............................. 5-6
5-3 Mounting of By-Pass Capacitors ...................................................... 5-7
5-4 Interference Reduction Design Technique for Rotary Inverter .......................... 5-9
5-5 Interference Reduction Design Technique for a Dynamotor ............................ 5-10
5-6 Power Line Transient Distribution of Amplitude ...................................... 5-12
5-7 Power Line Transient Distribution of Duration ........................................ 5-13
5-8 Power Line Transient Distribution of Rise Time ....................................... 5-14
5-9 Triangular Pulse Spectrum ........................................................... 5-15
5-10 Power Cable Degradation of Rise Time and Fall Time ................................. 5-16
5-1 I Transfer Function-Frequency Domain ................................................ 5-17
5-12 Typical Multiwire in Conduit Transfer Function ....................................... 5-18
5-13 Predicted Radio Interference Profile for 225-kV Power Line ............................ 5-19
5-14 Predicted Radio Interference Profile for 750-kV Power Line ............................ 5-20
5-15 Typical Frequency Spectra of the Interference Fields of High Voltage Power Lines ...... 5-21
5-1 6 Radio Noise Level vs Maximum Gradient ............................................. 5-23
5-17 Relative Current Spectrum of Corona and of a Gap Discharge ......................... 5-24
5-18 Relative Interference Field Strength as a Function of the Distance from the Line ........ 5-25
5-19 Reflection LOSSa nd Phase of a Three-conductor Bundle as a Function ofthe
Direction of Reflection .............................................................. 5-26
5-20 Spectra of Switching Interference Phenomena ......................................... 5-28
5-2 1 DC Switching Interference Reduction by Load-Shunt Diode ........................... 5-29
5-22 DC Switching Interference Reduction by Switch Shunt Diode .......................... 5-30
5-23 Current vs Voltage Characteristics of Two Back-to-Back Zener Diodes ................. 5-30
5-24 AC Switching Interference Reduction by Two Diodes .................................. 5-31
xxv
DARCOM-P 706410
LIST OF ILLUSTRATIONS (cont’d)
Figure No . Title Page
5-25 Series Capacitor and Resistor Circuit to Reduce Contact Erosion ....................... 5-31
5-26 Interference Reduction by Series Capacitor and Nonlinear Resistance .................. 5-32
5-27 Interference Reduction by Series Resistance and Parallel Capacitance ................... 5-32
5-28 Interference Reduction by Coupled Coils .............................................. 5-33
5-29 Interference Reduction by Coupled Coil With Diode ................................... 5-34
5-30 Interference Reduction Circuits Employing Bias Batteries .............................. 5-35
5-3 1 Composite Interference Reduction Components ....................................... 5-36
5-32 Typical Power Control Waveforms ................................................... 5-40
5-33 Objectionability of Lamp Flicker as a Function of Frequency .......................... 5-41
5-34 Typical Equivalent Circuit for a Power Source at Low Frequencies ..................... 5-42
5-35 Harmonic Content vs Function of Firing Angle (Unsymmetrical Phase Control) ........ 5-43
5-36 Harmonic Content vs Firing Angle (Symmetrical Phase Control) ....................... 5-44
5-37 Conducted Interference for Light Dimmer ............................................ 5-45
5-38 Conducted RFI Suppression With RF Ground Inaccessible ............................ 5-46
5-39 Conducted RFI Suppression With RF Ground Accessible .............................. 5-46
5-40 Decoupling Against Supply Transients ................................................ 5-47
5-4 1 Fluorescent Lamp Circuits ........................................................... 5-48
5-42 Dual Lamp Fluorescent Fixture ...................................................... 5-49
5-43 Conducted Interference from Fluorescent Lamps ...................................... 5-50
5-44 Conducted Interference from Three-lamp Fluorescent Fixture. With and
Without Filter ...................................................................... 5-51
5-45 Mutual Interference Coupling ........................................................ 5-52
5-46 Power Supply Filtering ............................................................... 5-54
5-47 Power Supply Isolation .............................................................. 5-55
5-48 Current Spectrum for Single-phase Rectifiers .......................................... 5-57
5-49 Current Spectrum for Single-phase Rectifiers Under Different Load Conditions ......... 5-58
5-50 Waveforms in the Half-wave Rectifier Circuit ......................................... 5-60
5-5 1 Single-phase Rectifiers ............................................................... 5-61
5-52 Six-phase Rectifiers .................................................................. 5-64
5-53 Three-phase Rectifiers ............................................................... 5-65
5-54 Power-line Filters .................................................................... 5-66
5-55 Effect of Different Load and Source Impedances on Insertion Loss ..................... 5-67
5-56 Common Mode Filtering ............................................................. 5-68
5-57 Line-to-ground Filtering ............................................................. 5-69
5-58 Magnetic Shielding Effectiveness for (A) a Single Thickness. and (B) a Double
Thickness of Material With High Permeability ....................................... 5-70
5-59 Series Regulator Block Diagram ...................................................... 5-70
5-60 Shunt Regulator Block Diagram ...................................................... 5-70
5-61 Switching Regulator Block Diagram .................................................. 5-71
5-62 L-C Transient Filter ................................................................. 5-72
5-63 Balanced L-C Transient Filter ........................................................ 5-72
5-64 Bifilar Transient Filter .............................................................. 5-72
5-65 Transient Suppression Circuits ....................................................... 5-73
5-66 Typical Vehicular Alternator Schematic ............................................... 5-76
5-67 Vibrating Type Voltage Regulator .................................................... 5-77
5-68 Suppression Applied to a Voltage Regulator ........................................... 5-78
5-69 Bonding of Shock-mounted Engine Rear Mount ....................................... 5-79
5-70 Battery Spark Ignition System ........................................................ 5-80
5-7 1 Emission from a Commercial Truck Having a Semiconductor Ignition System .......... 5-81
5-72 Emission from a Commercial Truck Having a Breaker-point Ignition System ............ 5-82
5-73 Integrally Shielded and Suppressed Spark Plug ........................................ 5-83
xxvi
DARCOM-P 706-410
LIST OF ILLUSTRATIONS (cont’d)
Figure No . Title Page
5-74 Integrally Suppressed and Shielded Coil and Distributor (Ignitor) ...................... 5-86
5-75 Waterproof Spark Plug Lead and Conduit Assembly ................................... 5-85
5-76 Emission from a Commercial Truck Having Semiconductor Ignition ................... 5-86
5-77 Schematic Diagram of a Typical Suppression System for Tactical Vehicles .............. 5-87
5-78 Receiver Power Line Susceptibility .................................................... 5-90
5-79 Receiver Block Diagram ............................................................. 5-91
5-80 Spurious Responses of Receiver Tuned to 3.0 MHz .................................... 5-93
5-8 1 RF Amplifier Characteristic.f, = 70 MHz ............................................ 5-94
5-82 Comparison of Third Order Distortion of a Microwave Amplifier vs a High Power
Millimeter Amplifier ................................................................ 5-95
5-83 Susceptibility of 49 DPSK to Antenna-coupled Interference ............................ 5-96
5-84 Probability of Bit Errors for PCM-FM With Continuous Antenna-coupled
Cochannel Interference (Af= 0.24) .................................................. 5-97
5-85 Successive Nyquist Pulses ............................................................ 5-98
5-86 Spectrum of Nyquist Pulse Showing Constancy of Repeated Spectrum .................. 5-99
5-87 Spectrum of Unfiltered Data Sequence ................................................ 5-100
5-88 Spectrum of Filtered Data Sequence .................................................. 5-101
5-89 Basic Elements of Product Modulators ................................................ 5-102
5-90 Calculated and Measured Results of the Typical Spectrum Distribution of
Sidebands Produced by Amplitude Modulated Transmitters .......................... 5- 104
5-9 1 Schematic Diagram of a Balanced Modulator ......................................... 5-105
5-92 Cosinusoidal Cap Waveform ......................................................... 5-106
5-93 Relative Intensity of Harmonics for Two Pulse Shapes as a Function of Conduction
Angle .............................................................................. 5-107
5-94 Typical Values of Harmonic Emissions Determined from Measurements on 14
Radio Transmitters ................................................................. 5-108
5-95 Harmonic Output as a Function of Beam Voltage for VA 87-B Klystron ................ 5-109
5-96 Single Carrier Power Transmission Characteristic and AM-PM Conversion Factor
for a Typical TWT .................................................................. 5-1 10
5-97 Diagram of Two Short-circuited Stubs (Each 1/4 wavelength long and spaced 1 /8
wavelength at the fundamental frequency) Arranged to Attenuate the Second
Harmonic .......................................................................... 5-1 10
5-98 Diagram Illustrating the Use of a Circulator to Separate Harmonics .................... 5-1 1 1
5-99 Measured Vaues of the Sideband Noise Level of Unmodulated 45- and 160-MHz
Transmitters as a Function of Frequency Separation from the Carrier Frequency ....... 5-1 1 1
5- 100 Measured Characteristics of Typical Radars ........................................... 5-1 19
5-101 Impedance of Center-fed Dipole ...................................................... 5-125
5- 102 (A) Far-field Radiation Patterns of Thin Dipoles (l/X = 0 to 1.5) ........................... 5-126
5-102 (B) Far-field Radiation Patterns ofThin Dipoles (I/X = 1.75 to 5) .......................... 5-127
5-103 Gain of Center-fed Dipole ............................................................ 5-128
5-104 Direction of Maximum Radiation Intensity for Center-fed Dipole and for Solid
Cone Over Hemispherical Ground ................................................... 5- 130
5- 105 Gain of 47-deg Solid Cone Above a Hemispherical Ground ............................ 5- 13 1
5-106 Far-field Radiation Patterns of Conical Antennas Above Infinite and Hemispherical
Ground ............................................................................ 5-132
5- 107 VSWR of Disc-cone Antennas ........................................................ 5-133
5- 108 Gain and VSWR of Horn Antenna With Transducer ................................... 5-134
5- I09 (A) Exponential Horn Azimuth Patterns, Vertical Polarization ............................. 5-1 36
5-109 (B) Exponential Horn Azimuth Patterns, Horizontal Polarization .......................... 5-1 37
5-1 10 Horn Patterns as Function of Frequency and Excitation Mode ......................... 5-1 38
5-1 11 Measured Pattern in dB of Horn Parabola Antenna at 3.74 GHz ........................ 5-139
xxvii