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RADHAZ Material Outline
Introduction and Background
Standards and Applications
Prediction of Electromagnetic Fields
Measurement of Electromagnetic Fields
Protective Devices
Procedures to Protect People
FCC Initiative in New Rule Making
Power Densities Measured Around the United States
LOCATION LEVELMicrowatt/(cm)2
Empire State Building(102nd floor) New York
32.5
Sears Tower(roof) Chicago
230
One Biscayne Tower(roof) Miami
148
Terrestrial Microwave Stations(base of Towers)
<1
Radar Emissions-PopulatedAreas (both commercial andmilitary)
50 (AVG)
Power Densities of Interest
watts/cm2 Milli Pico Watt/cm2 Receiver 1 X 10-15 Sensitivity Threshold
1 X 10-9 Nano Watt/cm2 Light from Venus
1 X 10-6 Micro Watt/cm2 Light from Full Moon
1 X 10-3 Milli Watt/cm2 IEEE LIMIT (30-300 MHz)
5 X 10-3 5 Milli Watt/cm2 FDA LIMIT On Microwave Ovens
100 X 10-3 100 Milli Watt/cm2 Sun Light NO TIME LIMIT
Conversion of SAR to Power Density
Threshold for Hazard Specific Absorption Rate (SAR) = 4 Watts/kg
Applying a Safety Factor 10 (SAR) = 0.4 Watts/kg
CONVERTING to POWER DENSITY: for HUMAN EXPOSURE
Average Man or Woman
WEIGHT = 60 kg
SURFACE AREA = 20,000 cm2
PH = POWER DENSITY for SAFETY THRESHOLD
PH = 0.4 Watts/kg
= 1.2 milli Watts/(cm)2
200,20
60
cm
kg
Band Definitions
VLF < 15 KHz LF 15 - 500 KHz MF 300 - 3000 KHz HF 2 - 30 MHz VHF 30 - 225 MHz UHF 225 - 800 MHz L-Band 800 - 1650 MHz S-Band 1650 - 3000 MHz C-Band 3000 - 7200 MHz X-Band 7200 - 10,500 MHz Ku-Band 10,500 - 16,000 MHz K-Band 16,000 - 26,000 MHz Ka-Band 26,000 - 40,000 MHz V-Band 36,000 - 52,000 MHz
Transmit Power of Various Systems
AM Radio MF - HF 500 - 50 KW
FM Radio VHF 5 - 30 KW
TV Low VHF (Channels 1-6) 3 - 10 KW
TV High VHF (Channels 7-13) 10 - 100 KW
TV UFH (Channels 14-89) 1000 - 5000 KW
Radar Peak Power (UHF-Ka-Band) 50 - 5000 KW
Radar Average Power 100 - 5 KW
Human Response to RF Levels
REFERENCE
1 Watt/kg Basal Metabolism Rate
1.4 Watt/kg Resting Metabolism Rate
5-8 Watt/kg Exercise
18 Watt/kg Maximal Exercise
Lying on Beach Sunning 80 - 100 milli Watts/cm2
Threshold of Feeling (2300 MHz) 26 milli Watts/cm2
Threshold of Feeling (infrared) 1.6 milli Watts/cm2
Occupational DistributionOCCUPATION % of POPULATION
Industrial 1.9
Medical 3.0
Military 2.1
Science & Research 1.6
Aviation 1.5
Marine 6.6
Service 8.8
Communication 73.0
Hazards Electromagnetic Radiation To
Personnel (HERP) Fuels (HERF) Ordnance (HERO)
Controlling Documentation on Safety
FCC OET Bulletin 65 FCC Report & Order 96-326 ANSI/IEEE C95.1-1992 DoD Inst 6055.11 Personnel Exposure NAVSEA OP3565/NAVAIR 16-1-529 Vol I HERP and HERF Limits NAVSEA OP3565/NAVAIR 16-1-529 Vol II HERO Limits
FCC Limits for Maximum Permissible Exposure (MPE)
Plane-wave Equivalent Power Density
FrequencyRange(MHz)
ElectricField
Strength (E)(V/m)
MagneticField
Strength (H)(A/m)
PowerDensity (S)(mW/cm2)
AveragingTime E 2,
or H 2 or S(minutes)
0.3-3.0 614 1.63 (100)* 6
3.0-30 1842/f 4.89/f (900/f2)* 6
30-300 61.4 0.163 1.0 6
300-1500 ------ ------ F/300 6
1500-100,000 ------ ------ 5 6
f=frequency in MHz
* Plane-wave equivalent power density
FCC Limits for Occupational/Controlled Exposure
FCC Limits for General Population/Uncontrolled Exposure
FrequencyRange(MHz)
ElectricField
Strength (E)(V/m)
MagneticField
Strength (H)(A/m)
PowerDensity (S)(mW/cm2)
AveragingTime E 2, H 2 or S(minutes)
0.3-1.34 614 1.63 (100)* 30
1.34-30 842/f 2.19/f (180/f2)* 30
30-300 7.5 0.073 0.2 30
300-1500 ------ ------ F/1500 30
1500-100,000 ------ ------ 1.0 30
f=frequency in MHz
* Plane-wave equivalent power density
IEEEMaximum Permissible Exposure for Controlled
Environments
Part A Electromagnetic Fields
1 2 3 4 5
Frequency Electric Field Magnetic Field Power Density (s) Averaging Range Strength (E) Strength (H) E = Field, H-Field Time (MHz) (V/m) (A/m) (mW/cm 2) |E|2, |H|2 or S (minutes)
0.003 - 0.1 614 163 (100, 1 000 000) 6 0.1 - 3.0 614 16.3/ (100, 10 000/2) 6 3 - 30 1842/ 16.3/ (900/f2, 10 000/f2) 6 30 -100 61.4 16.3/ (1.0, 10 000/f2) 6 100 - 300 61.4 0.163 1.0 6 300 - 3000 /300 6 3000 - 15000 10 6 15000 - 300000 10 616 000/f 1.2
IEEEMaximum Permissible Exposure for Uncontrolled Environments
Part A Electromagnetic Fields
1 2 3 4 5
Frequency Electric Field Magnetic Field Power Density (s) Averaging Range Strength (E) Strength (H) E = Field, H-Field Time (MHz) (V/m) (A/m) (mW/cm 2) |E|2, S or |H|2 (minutes) 0.003 - 0.1 614 163 (100, 1 000 000) 6 6
0.1 - 1.34 614 16.3/ (100, 10 000/2) 6 6 1.34 -3.0 823.8/ 16.3/ (180/f2, 10 000/2) f2/0.3 6 3.0 - 30 823.8/ 16.3/ (180/f2, 10 000/2) 30 6 30 - 100 27.5 158.3/1.668 (0.2, 940 000/3.336) 30 0.0636
1.337 100 - 300 27.5 0.0729 0.2 30 30 300 - 3000 /1500 30 3000 - 15000 /1500 90 000/ 15000 - 300000 10 616 000/ 1.2
Near Field and Transition ZoneDistance Calculation
Where,
N = Extent of Near Field Zone, Meters T = Extent of Transition Zone, Meters D = Antenna Diameter, Meters = Wavelength, Meters
4
2DN
2*6.0 DT
Near Field Calculation
Where,
PD = Near Field Power Density, Watts/(meter)2
P = Power Output of System, Watts E = Antenna Efficiency, Number (one or less) A = Antenna Area, (meter)2
A
PEPD
**4
Transition Zone Calculation
Where, (PDT) = Transition Zone Power Density,Watts/(meter)2
(PD) = Power Density in Near FIeld, Watts/(meter)2
R = Distance to Point of Interest, Meters N = Near Field Zone Distance, Meters
R
NPDPDT
))(()(
Far Field and Off-Axis Calculation
Where, PDF = Power Density in the Far Field or Off-Axis in the Near Field or
Transition Zone, Watts/(meter)2
P = Power Delivered to the Antenna, Watts G = Gain of the Antenna Relative to an isotropic in the direction of
Interest, Number R = Distance to the Point of Interest, meters
2*4
*
R
GPPDF