Attachment Exhibit C

This document pretains to SES-LIC-20170928-01070 for License on a Satellite Earth Station filing.

IBFS_SESLIC2017092801070_1282836

                             RADIATION HAZARD CALCULATIONS FOR                 2.4 meter EARTH STATION


              Nomenclature                 Formula                   Value Unit


        INPUT PARAMETERS

D = Antenna Dlameter                                                   2.40| meters

d = Diameter of Feed Mouth                                           0.133     meters

P = Max Powerinto Antenna                                                    5| Watts


n = Apperture Effeciency                                               64%

k =Wavelength @ 30 GHz                                              0.0467 meters


       CALCULATED VALUES

A= Area of Reflector                      PID®214                    4.524     meters*2

1= Length of Near Field                    D*2/4k                       31     meters

L = Beginning of Far Field                0.6D*27k                      74     meters

G = Antenna Gain @ 30 GHz                n(PI*O/k)®2                16,690 142.2 dBi


a = Area of Feed Mouth                     PI"d"214                 0.0139 meters*2


               POWER DENSITY CALCULATIONS


                                              Maximum Power Density in Region
                Region                                                                 Hazard Assessment
                                           Formula             Value (mWicm*2) |(FCC MPE Limit = 5 mW/cm*2)


1 Near Field                                4nP/A                      0.28             <FCC MPE Limit

2 Far Field                             GP/4(PIL®2)                    0.12             <FCC MPE Limit

3 Transition                           <= Nr Fid Region                0.28             <FCC MPE Limit

4 Near Reflector Surface                    4PIA                       0.44             <FCC MPE Limit

5 Between Reflector & Ground                 PA                        0.11             <FCC MPE Limit

6 Between Reflector and Feed                4Pla                     144.0          > FCC MPE Limit (See Attachment 1)


                                          RADIATION HAZARD ANALYSIS
                                           2.4 meter EARTH STATION

  This analysis calculates the non—ionizing radiation levels due to transmission from the earth station.
[The Office of Engineering and Technology (OET) Bulletin No, 65 specifies that the Maximum Permissible
Exposure (MPE) limit for the persons in an Occupational/Controlled environment to non—lonizing radiation
averaged over six minutes, is a power density of 5 milli—Watts per meter squared.

  The analysis estimates the maximum powerdensity levels in the vicinity of the antenna for six regions:
near field; far field; transition zone; near the reflector surface; between the reflector and the ground; and
between the feed mouth and the reflector.

  A brief discusion for each region is given below. The attached table shows the assumptions, formulae and
calculations for all cases.


1. NEAR FIELD REGION
  The near field (or Fresnel region) is essentially a cylindrical region with its axis co—incident with the
antena boresight. The diameter of this cylinder is equal to that of the antenna. According to OET Bulletin
No. 65, its length is equal to the square of the diameter divided by four times the wavelength. The maximum
value of the on—axis power density is calculated using the equation given in the Bulletin,

2. FAR FIELD REGION
  The far field (or Fraunhofer region) extends outwards from a distance equal to 0.6 times the square of the
reflector diameter divided by the wavelength, according to OET Bulletin No. 65. Powerdensity varies inversely
aas the square of the distance. The maximum value of the power density is calculated using the equation given
in the Bulletin.

3. TRANSITION REGION
  The transition region between the nearfield and the far field regions will have a power density that
maximum essentially decreases inversely as distance. in any case, the maximum powerdensity will not exceed
the value calculated for the near field region, for the purpose of evaluating potential exposure.

4. REGION NEAR REFLECTOR SURFACE
  The power density in the region near the reflector surface can be estimated as equal to four times the power
divided by the area of the reflector surface, assuming that the illumination is uniform and that it would be
possible to intercept equal amounts of energy radiated towards and reflected from the reflector surface.

5. REGION BETWEEN REFLECTOR AND GROUND
  The power density in the region between the reflector and the ground can be estimated as equalto the power
divided by the area of the reflector surface, assuming even illumination over the reflector.

6. REGION BETEEN THE FEED MOUTH AND REFLECTOR
  The radiation from the feed is essentially confined to a conical region whose vertex is located at the
feed mouth and extendsto the reflector. Power density is maximum at the feed mouth, and can be estimated
aas four times the output power divided by the area of the feed mouth.

    The analysis shows that the power density levels will never exceed the FCC MPE limit even during periods
lof maximum output, except in the region between the feed and the reflector. To ensure compliance with the
FCC MPE limit, the earth station transmitter will be turned off whenever maintenance and repair personnel are
required to work within this potentially hazardous area.



Document Created: 2017-09-28 13:29:21
Document Modified: 2017-09-28 13:29:21

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