RADHAZ Lecture Part1 by tjP2ikl

VIEWS: 13 PAGES: 19

									            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                  LEVEL
                                       Microwatt/(cm)2
      Empire State Building                 32.5
      (102nd floor) New York

      Sears Tower                           230
      (roof) Chicago

      One Biscayne Tower                    148
      (roof) Miami

      Terrestrial Microwave Stations         <1
      (base of Towers)

      Radar Emissions-Populated           50 (AVG)
      Areas (both commercial and
      military)
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
                                     60 kg
             PH = 0.4 Watts/kg    20 ,00 cm 2
             = 1.2 milli Watts/(cm)2
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 Distribution
          OCCUPATION           % 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
FCC Limits for Occupational/Controlled
Exposure

      Frequency         Electric        Magnetic        Power        Averaging
        Range             Field            Field      Density (S)   Time E2,
        (MHz)         Strength (E)     Strength (H)    (mW/cm2)     or H2 or S
                         (V/m)            (A/m)                      (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 General
Population/Uncontrolled Exposure

     Frequency        Electric      Magnetic        Power       Averaging
       Range            Field          Field      Density (S)   Time E2,
       (MHz)        Strength (E)   Strength (H)    (mW/cm2)      H2 or S
                       (V/m)          (A/m)                     (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
                        IEEE
Maximum 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
                                     IEEE
            Maximum 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)      f 2/0.3            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 Zone
Distance Calculation

                                 D2
                             N 
                                 4
                                                2
                                  0.6 * D
                       T 
Where,
                                            
    N = Extent of Near Field Zone, Meters
    T = Extent of Transition Zone, Meters
    D = Antenna Diameter, Meters
     = Wavelength, Meters
   Near Field Calculation


              4* E * P
         PD 
                 A
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
Transition Zone Calculation


             ( PD)( N )
   ( PDT ) 
                 R
 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
Far Field and Off-Axis Calculation


            P *G
     PDF 
           4 * R 2

   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

								
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