Attachment RADHAZ

This document pretains to SES-MOD-20170508-00540 for Modification on a Satellite Earth Station filing.

IBFS_SESMOD2017050800540_1215082

6/25/2010 Page 1 Analysis of Non-Ionizing Radiation for a Vertex 3.8 Meter Antenna This report presents an analysis of the non-ionizing radiation levels for a 3.8 meter Vertex RSI Satellite Earth Station. The calculations used in this analysis were derived from and comply with the procedures outlined in the Federal Communication Commission, Office of Engineering and Technology Bulletin Number 65, which establishes guidelines for human exposure to Radio Frequency Electromagnetic Fields. Bulletin 65 defines exposure levels in two separate categories, the General Population/Uncontrolled Areas limits, and the Occupational/Controlled Area limits. The Maximum Permissible Exposure (MPE) limit of the General Population/Uncontrolled Area is defined in Table (1), and represents a maximum exposure limit averaged over a 30 minute period. The MPE limit of the Occupational/Controlled Area is defined in Table (2), and represents a maximum exposure limit averaged over a 6 minute period. The purpose of this report is to provide an analysis of the earth station power flux densities, and to compare those levels to the specified MPE’s. This report provides predicted density levels in the near field, far field, transition region, main reflector surface area, area between the main reflector and sub reflector or feed assembly, as well as the area between the antenna edge and ground. MPE Limits for General Population/Uncontrolled Area Frequency Range (MHz) Power Density (mW/cm2) 1500 – 100,000 1.0 Table 1 MPE Limits for Occupational/Controlled Area Frequency Range (MHz) Power Density (mW/cm2) 1500 – 100,000 5.0 Table 2

6/25/2010 Page 2 3.8 Meter Vertex RSI Table 3 contains formulas, equations and parameters that were used in determining the Power Flux Density levels for the Vertex RSI 3.8M: Data Type Data Data Formula Data Value Unit of Symbol Measure Power Input P Input 16 W Antenna Size D Input 3.8 M Antenna Area A A = (Π D 2 ) ÷ 4 11.34 M2 Subreflector Size Sub Input 19.1 cm Subreflector Area Asub Asub = (ΠSub 2 ) ÷ 4 286.52 cm2 Gain dBi Gdbi Input 53 dBi Gain Factor G G = 10Gdbi/10 199526.23 Gain Factor Frequency f Input 14250 MHz Wavelength λ 299.79 / f 0.021038 Meters Aperture Efficiency η η = [(Gλ 2 ) ÷ (4Π )] ÷ A .62 n/a Pi Π Input 3.14159 Numeric Constant M/Sec Input 299,792,458 Numeric Conversion W to mW mW mW = W × 1000 n/a n/a Conversion M to cm cm cm = M × 100 n/a n/a Conversion M2 to cm2 cm2 cm2 = M 2 × 10000 n/a n/a Conversion W/M2 to mW/cm2 mW/cm2 = W / M 2 ÷ 10 n/a n/a mW/cm2 Table 3 1. Far Field Analysis The distance to the far field can be calculated using the following formula: 0.6 D 2 R ff = = 411.8 Meters λ The power density in the far field can be calculated using the following formula. Note: this formula requires the use of power in milliwatts and far field distance in centimeters, or requires a post calculation conversion from W/M2: PG S ff = = 0.150 mW/cm2 4Π R ff 2

6/25/2010 Page 3 2. Near Field Analysis The extent of the Near Field region can be calculated using the following formula: D2 Rnf = = 171.6 Meters 4λ The power density of the near field can be calculated using the following formula. Note: this formula requires the use of power in milliwatts and diameter in centimeters, or requires a post calculation conversion from W/M2: 16ηP S nf = = 0.350 mW/cm2 ΠD 2 3. Transition Region Analysis The transition region extends from the end of the near field out to the beginning of the far field. The power density in the transition region decreases inversely with distance from the antenna, while power density in the far-field decreases inversely with the square of the distance. However the power density in the transition region will not exceed the density in the near field, and can be calculated for any point in the transition region (R), using the following formula. Note: This formula requires the use of distance in centimeters, or requires a post calculation conversion from W/M2. S nf Rnf St = = 0.350 mW/cm2 R 4. Main Reflector Surface Area Analysis The maximum power density at the antenna surface area can be calculated using the following formula. Note: this formula requires the use of Power in milliwatts and Area in centimeters squared, or requires a post calculation conversion from W/M2. 4P S surface = = 0.564 mW/cm2 A

6/25/2010 Page 4 5. Subreflector Area Analysis The area between the sub reflector and main reflector presents a potential hazard, with the highest density being located at the sub reflector area. The power density at the sub reflector can be calculated using the following formula. Note: this formula requires the use of Power in milliwatts and Area in centimeters squared, or requires a post calculation conversion from W/M2. 4P Subsurface = = 223.370 mW/cm2 Asub 6. Power Density between Reflector and Ground Analysis The power density between the reflector and the ground can be calculated using the following formula. Note: this formula requires the use of Power in milliwatts and Area in centimeters squared, or requires a post calculation conversion from W/M2. P S ground = = 0.141 mW/cm2 A Tables 4 and 5 present a summary of the radiation hazard findings on the Vertex 3.8M terminal for both the General Population/Uncontrolled Area, as well as the Occupational/Controlled area environments. MPE Limits for General Population/Uncontrolled Area Area Range Power Density Finding Meters (mW/cm2) Far Field 411.8 0.150 mW/cm2 Meets FCC requirements Near Field 171.6 0.350 mW/cm2 Meets FCC requirements Transition Region 171.6 – 411.8 0.350 mW/cm2 Meets FCC requirements Main Reflector Surface N/A 0.564 mW/cm2 Meets FCC requirements Sub-reflector Surface N/A 223.370 mW/cm2 Potential Hazard Area between Reflector N/A 0.141 mW/cm2 Meets FCC and Ground requirements Table 4

6/25/2010 Page 5 MPE Limits for Occupational/Controlled Area Area Range Power Density Finding Meters (mW/cm2) Far Field 411.8 0.150 mW/cm2 Meets FCC requirements Near Field 171.6 0.350 mW/cm2 Meets FCC requirements Transition Region 171.6 – 411.8 0.350 mW/cm2 Meets FCC requirements Main Reflector Surface N/A 0.564 mW/cm2 Meets FCC requirements Sub-reflector Surface N/A 223.370 mW/cm2 Potential Hazard Area between Reflector N/A 0.141 mW/cm2 Meets FCC and Ground requirements Table 5 Based on the above finding there is a potential hazard of radio frequency exposure with use of the Vertex RSI 3.8M. In order to mitigate the risk of these hazards, this terminal will only be operated in a controlled area, and the unit will be shut down prior to performing maintenance in any of the occupational hazard areas.


Document Created: 2010-06-25 14:23:51
Document Modified: 2010-06-25 14:23:51
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