Attachment K46 Radiation Hazard

This document pretains to SES-LIC-20140506-00336 for License on a Satellite Earth Station filing.

IBFS_SESLIC2014050600336_1033194

                                 RF Radiation Hazard Analysis
                                               PSSI K46 2.4m


Antenna Diameter (D) = 2.4 meters, 240 cm
Antenna Surface Area (SA) = 4.524 m², 45240.00 cm²
Sub-reflector Diameter (DS) = N/A
Sub-reflector Surface Area (AS) = N/A
C-Band Wavelength at 14.250 GHz Center Band, LAMBDA = .021 meters, 2.1 cm
Power at output at HPA = 400 watts
Path Loss to OMT (IL) = 1.25 dB
Power at OMT Flange (P) = 300 watts
Antenna Gain at 6.1750 GHz (G) = 48.0 dBi
                                                      4
Antenna Gain given in Power Ratio (GES) = 6.3095-10
Antenna Aperture Efficiency (N) = .627 or 62.7%


Region                                            Radiation Level                  Hazard Assessment

Far Field (RF) = 16,457 cm, 164.57 meters          5.5616 mW/cm²                   Potential Hazard
Near Field (RN) = 6857cm, 68.57meters                 16.6 mW/cm²                  Potential Hazard
Transition Region (RT) ≤                              16.6 mW/cm²                  Potential Hazard
Sub-Reflector Region (WS)                                0 mW/cm²                  Potential Hazard
Main Reflector Region (WM)                            26.5 mW/cm²                  Potential Hazard
Power Density between Reflector and Ground            6.63 mW/cm²                  Potential Hazard
Power Density between Reflector Edge and Ground    0.0276 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,
which is mounted on top of a truck, is 12 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 personnel or public will be able to have access to the main reflector area. 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 K46 2.4m – Supporting Calculations


Antenna Diameter, (D) = ………………                  D = 2.4 m D = 240 cm

Antenna Surface Area, (Sa) =………….               Sa =   (D  D/4)     Sa = 4.524 sq m Sa = 45240.00 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 = 14.250 GHz

Wavelength at (Cf), (λ) =……….                   λ = .021 meters λ = 2.1 cm

Transmit Power at HPA Flange, (P1) =...         P1 = 400 Watts       P2 = log (P1)10 P2 = 26.02 dBw

Path Loss from HPA to OMT, (Loss) =...          Loss = .25 dB

HPA Back off from Saturation, (Loss2) =.        Loss 2 = 1.0 dB

Power at OMT, (P) =……                           P3 = P2-Loss-Loss2 P3 = 24.77 dBw (OMT power in dBw)
                                                P = 10 P3/10 P = 300.00 Watts (OMT in Watts)

Antenna Gain at (Cf), (Gain) =…………              Gain = 48.00 dBi

Antenna Gain/ Power Ratio, (Ges) =…...          Ges = 10Gain/10 Ges = 6.3095-104 Ratio

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


Far Field (Rf) =   Rf = (0.6  (D  D))/ λ     Rf = 164.57 meters Rf = 16,457 cm
Far Field Pwr Density (Wf) =    Wf = (Ges  P)/4    (Rf  Rf) Wf = 0.0055616 W/cm² Wf = 5.5616 mW/cm²
Near Field (Rn) = Rn = (D  D)/4  λ         Rn = 6857 cm
Near Field Pwr Density (Wn) = Wn = ((16  n  P)/   (D  D))         Wn = 0.0166 W/cm² Wn = 16.6 mW/cm²

Transition Region (Rt) =   Rt = Wn  1       Rt ≤ 16.6 mW/cm²
Pwr Density at Sub Reflector (Ws) = Ws = (4  P)/ As          Ws = 0 W/cm²      Ws = 0 mW/cm²
Main Reflector Region Pwr Density (Wm) = Wm = (4  P)/ Sa              Wm = 0.0265 W/cm² Wm = 26.5 mW/cm²
Pwr Density / Main Reflector and Ground (Wg) = Wg = (P/Sa)              Wg = 6.63 mW/cm²
Pwr Density / Reflector Edge and Ground (WI) = WI = Wg/D               WI = 0.0276 mW/cm²



Document Created: 2014-01-17 14:11:39
Document Modified: 2014-01-17 14:11:39

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