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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