Attachment CK32 Hazard Studay

This document pretains to SES-LIC-20130710-00578 for License on a Satellite Earth Station filing.

IBFS_SESLIC2013071000578_1003345

                                RF Radiation Hazard Analysis
                                               PSSI CK32 4.5


Antenna Diameter (D) = 4.5 meters, 450 cm
Antenna Surface Area (SA) = 159043.0 sq. cm
Sub-reflector Diameter (DS) = 0 cm
Sub-reflector Surface Area (AS) = 0 sq. cm
C-Band Wavelength at 6.175 GHz Center Band, LAMBDA = .049 meters, 4.90 cm
Power at output at HPA = 500 watts
Path Loss to OMT (IL) = 3.15 dB
Power at OMT Flange (P) = 241.55 watts
Antenna Gain at 6.1750 GHz (G) = 46.9 dBi
Antenna Gain given in Power Ratio (GES) = 4.8977E+4
Antenna Aperture Efficiency (N) = .627 or 62.7%


Region                                            Radiation Level                 Hazard Assessment

Far Field (RF) = 24796 cm, 247.96 meters           1.5312 mW/cm²                  Potential Hazard
Near Field (RN) = 10331 cm, 103.31 meters           3.809 mW/cm²                  Potential Hazard
Transition Region (RT) ≤                            3.809 mW/cm²                  Potential Hazard
Sub-Reflector Region (WS)                               0 mW/cm²                  Satisfies ANSI
Main Reflector Region (WM)                          3.037 mW/cm²                  Potential Hazard
Power Density between Reflector and Ground         1.5187 mW/cm²                  Potential Hazard
Power Density between Reflector Edge and Ground    0.3375 mW/cm²                  Satisfies ANSI


Conclusion:

Based on the above analysis, harmful areas of radiation do exist in areas around the antenna and in the path of the
antenna toward the satellite that it is pointed. The area occupied by the general public, “uncontrolled environment”, will
not exceed the ANSI limit of 1mW/cm² because precautions will be taken to warn, educate and limit the access of
personnel around the areas of the antenna and its path that may pose a radiation hazard. The bottom edge of the antenna
is 8 feet high when deployed which moves the hazard away from the public. Normal look angles for domestic operation
move the potential hazard even further away from the general public. As well during operation no maintenance,
operation or public will be able to have access to the area around the sub-reflector region. This area has the greatest
concentration of radiation, but fortunately is not accessible during operation due to the operational angle of the antenna
and the height above ground level. In addition the antenna will be marked with the standard radiation hazard signs. The
warning signs will warn personnel to avoid the area around and in front of the reflector when the transmitter is
operational. To ensure compliance with safety limits, the Earth Station transmitters will be turned off and marked to
remain off whenever maintenance and repair personnel are required to work in the areas of potential hazard as defined in
the above study. Additionally, all Earth Station personnel will be trained to insure that the antenna path is clear at all
times while the transmitter is in operation.


                Note: See the following sheet for how the above calculations were made.


                                   Analysis of Non-Ionizing Radiation
                                   PSSI CK30 4.6 – Supporting Calculations


Antenna Diameter, (D) = ………………                  D = 4.5 m   D = 450 cm

Antenna Surface Area, (Sa) =………….               Sa =   (D  D/4)    Sa = 15.9043 sq. m Sa = 159043.0 cm²

Sub Reflector Diameter, (Ds) =………..             Ds = 0 m         Ds = 0 cm

Sub Reflector Area, (As) =…………….                As =   (Ds  Ds/4) As = 0 m² As = 0 cm²

Center Frequency, (Cf) =………………                  Cf = 6.175 GHz

Wavelength at (Cf), (λ) =……….                   λ = .049 meters λ = 4.9 cm

Transmit Power at HPA Flange, (P1) =...         P1 = 500 Watts       P2 = log (P1)10   P2 = 26.98 dBw

Path Loss from HPA to OMT, (Loss) =...          Loss = .65 dB

HPA Back off from Saturation, (Loss2) =.        Loss 2 = 2.5 dB

Power at OMT, (P) =……                           P3 = P2-Loss-Loss2 P3 = 23.83 dBw (OMT power in dBw)
                                                P = 10 P3/10 P = 241.55 Watts (OMT in Watts)

Antenna Gain at (Cf), (Gain) =…………              Gain = 46.9 dBi

Antenna Gain/ Power Ratio, (Ges) =…...          Ges = 10Gain/10 Ges = 4.8977-104 Ratio

Antenna Aperture Efficiency, (n) =…….           n = .627 or n = 62.7%


Far Field (Rf) =   Rf = (0.6  (D  D))/ λ     Rf = 247.96 meters Rf = 24796 cm

Far Field Pwr Density (Wf) = Wf = (Ges  P)/(4  )  (Rf  Rf) Wf = 0.0015312 W/cm² Wf = 1.5312 mW/cm²
Near Field (Rn) = Rn = (D  D)/4  λ         Rn = 10331.63 cm

Near Field Pwr Density (Wn) = Wn = ((16  n  P)/   (D  D)) Wn = 0.003809 W/cm² Wn = 3.809 mW/cm²

Transition Region (Rt) =   Rt = Wn  1       Rt ≤ 3.809 mW/cm²
Pwr Density at Sub Reflector (Ws) = Ws = (2  P)/ As          Ws = 0 W/cm²       Ws = 0 mW/cm²
Main Reflector Region Pwr Density (Wm) = Wm = (2  P)/ Sa              Wm = 0.003037 W/cm² Wm = 3.037 mW/cm²
Pwr Density / Main Reflector and Ground (Wg) = Wg = (P/Sa)              Wg = 1.5187 mW/cm²
Pwr Density / Reflector Edge and Ground (WI) = WI = Wg/D               WI = 0.3375 mW/cm²



Document Created: 2013-05-08 09:12:49
Document Modified: 2013-05-08 09:12:49

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