Attachment Radiation REport

This document pretains to SES-LIC-INTR2010-02985 for License on a Satellite Earth Station filing.

IBFS_SESLICINTR201002985_841279

Radiation Hazard                                                                                             Page 1 of 3

           Analysis of Non-Ionizing Radiation for an 9.0 meter Earth Station
                                  at Maximum EIRP.
  This report analyzes the Non-Ionizing radiation levels for an 9.0 meter Earth Station. The offices of Science and
Technology Bulletin, Number 65, October 1985, specifies that the maximum level of Non-Ionizing radiation that
a person may be exposed to over a six minute period is an average power density equal to 5 mW / cm^2. It is
the purpose of this report to determine the power flux densities radiated by the Earth Station in the Far Field,
the Near Field, Transition Region, Between the Feed Flange and the Reflector Surface, at the Reflector Surface,
between the antenna edge and the ground, and on the other side of a steel reinforced concrete structure.
  The Chinese maximum exposure limit is much more conservative at 0.038 mW / cm^2. This standard does
not have an exposure time limitation, and is therefore much lower to account for the possibility of continuous
exposure.

Calculation Parameters :
The following parameters were used to calculate the various power flux densities radiated by this Earth Station.
     Antenna Manufacturer                          Vertex/RSI
     Antenna Model                                       9.0M     value         units
     Antenna Diameter                                     D=          9.000 meters
     Antenna Surface Area                                 A=          63.62 meters ^2
     Feed Flange Diameter                                 Df =        0.100 meters
     Area of Feed Flange                                  Af =       0.0079 meters^2
     Wavelength at       14.0 GHz                  Lambda =           0.021 meters
     Transmit Power at HPA Flange                       HPA =    1000.000 Watts
     Losses to Antenna Flange                              L=         4.000 dB (+)
     Transmit Power at Antenna Input Flange                P=       398.11 Watts
     Antenna Gain at     14.0 GHz                         G=         60.100 dBi
     Antenna Gain (ratio using 10^(60.1/10))              G = 1,023,293.0
     PI                                                   PI =   3.141593
     Antenna Aperture efficiency                           n=          0.59

Summary of Expected Radiation Levels :
Far Field Calculations                                  Calculated Value       units            Hazard?
     Distance to Far Field Region                          Rf =     2268.00 meters
     Power Density in Far Field Region                    Wf =         0.63 mW / cm^2 Satisfies ANSI

Near Field Calculations
    Extent of Near Field Region                           Rn =        945.00 meters
    Power Density in Near Field Region                    Wn =          1.47 mW / cm^2 Satisfies ANSI

Transition Region Calculations
    Power Density in Transition Region                    Wn =           1.47 mW / cm^2 Satisfies ANSI

Region between Feed Flange and Reflector
    Power Density at Feed Flange                          Wfl =   10,137.72 mW / cm^2 Potential Hazard

Reflector Region
     Power Density at Reflector Surface                    Wr =          1.25 mW / cm^2 Satisfies ANSI

Region between Reflector and Ground
    Power Density at Edge of Reflector Surface            Wg =         0.013 mW / cm^2 Satisfies ANSI

Region on other side of Reinforced Concrete
    Transmitted Power Density                              Wt =      0.00013 mW / cm^2 Satisfies ANSI

Note: Calculations are at the maximum allowable power level for an antenna this size.


Radiation Hazard                                                                                            Page 2 of 3

          Analysis of Non-Ionizing Radiation for an 9.0 meter Earth Station
                           at Maximum EIRP. (Continued)

Calculation Details :

Far Field Calculations
This region is contained within a roughly conical volume having the same diameter as the antenna at the
beginning of the far field. The value calculated below is the maximum power in the volume. The power density
in this region decreases inversely with the square of the distance.

     Distance to the beginning of the Far Field Region    Rf = 0.60 * D^2 / Lambda (meters)
                                                          Rf =     2268.00 meters

     Maximum Power Density in Far Field Region            Wf = G * P / 4 * PI *Rf^2 (mW / cm^2)
                                                          Wf =          0.63 mW / cm^2

Near Field Calculations
Power flux density is considered to be at a maximum value throughout the entire length of the defined region.
The region is contained within a cylindrical volume having the same diameter as the antenna. Past the
extent of the near field region the power density decreases with distance from the transmitting antenna.

     Distance to the end of the Near Field Region         Rn = D^2 / 4 * Lambda (meters)
     (extent of the near field)                           Rn =      945.00 meters

     Power Density in Near Field Region                   Wn = 16 * n * P / PI * D^2 (mW / cm^2)
                                                          Wn =          1.47 mW / cm^2

Transition Region Calculations
The transition region is located between the near field and far field regions. As stated above, the power
density begins to decrease with distance in the transition region. While the power density decreases inversely
with the distance in the transition region. The power density decreases inversely with the square of the
distance in the far field region. The maximum power density in the transition region will not exceed that
calculated for the near field region (1.47 mW/cm^2), as shown above.

Region between Feed Flange and Reflector
Transmissions from the feed horn are directed toward the reflector surface, and are confined within a conical
shape defined by the feed. The maximum energy density between the feed and reflector surface is at the
apex of the cone (at the feed horn flange) This power density can be calculated as follows:

     Power Density at Feed Flange                         Wfl = 2 * P / Af (mW / cm^2)
                                                          Wfl = 10,137.72 mW / cm^2

Reflector Region
The power density in the reflector region is determined in the same manner as the power density at the feed
flange, above, but the area is now the area of the reflector aperture.

     Power Density at Reflector Surface                   Wr = 2 * P / A (mW / cm^2)
                                                          Wr =          1.25 mW / cm^2


Radiation Hazard                                                                                               Page 3 of 3

           Analysis of Non-Ionizing Radiation for an 9.0 meter Earth Station
                            at Maximum EIRP. (Continued)

Calculation Details (continued) :

Region between Reflector and Ground
Assuming uniform illumination of the reflector surface, the power density between the antenna and ground
can be approximated using a formula from the Offices of Science and Technology Bulletin, Number 65,
October 1985, Page 18, as follows:

     Power Density between Reflector and ground            Wg = Wr * 10 ^(-20/10) (mW / cm^2)
                                                           Wg =       0.013 mW / cm^2

Transmission through steel reinforced concrete
Assuming steel reinforced concrete of a thickness greater than 1/2 of the wavelength of the incident illumination,
(1.07 cm.) the transmission attenuation is greater than 20 dB. This results in a transmitted power as follows:

     Transmitted Power Density                              Wt = Wg * (10 ^(-20/10)) (mW / cm^2)
                                                            Wt =    0.00013 mW / cm^2


Conclusions :
     Based on the analysis, it is concluded that harmful levels of radiation will not occur in the regions accessible
by people. Fencing, padlocks, and/or signs will be used to restrict access of the public and operating
personnel to areas where the radiation level exceeds the ANSI standard . The transmitter will be turned off
during maintenance activities so that the ANSI standard of 5 mW / cm^2 will be complied with for those
regions that exceed acceptable levels.



Document Created: 2010-09-07 10:16:53
Document Modified: 2010-09-07 10:16:53

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