Attachment Exhibit B

This document pretains to SES-MOD-20100602-00666 for Modification on a Satellite Earth Station filing.

IBFS_SESMOD2010060200666_820150

                                                                                         Exhibit B
Radiation Hazard Report                                                                  Page 1 of 5


      Analysis of Non-Ionizing Radiation for a 3.8-Meter Earth
                          Station System
This report analyzes the non-ionizing radiation levels for a 3.8-meter earth station system. The analysis and
calculations performed in this report comply with the methods described in the FCC Office of Engineering
and Technology Bulletin, No. 65 first published in 1985 and revised in 1997 in Edition 97-01. The radiation
safety limits used in the analysis are in conformance with the FCC R&O 96-326. Bulletin No. 65 and the
FCC R&O specifies that there are two separate tiers of exposure limits that are dependant on the situation in
which the exposure takes place and/or the status of the individuals who are subject to the exposure. The
Maximum Permissible Exposure (MPE) limits for persons in a General Population/Uncontrolled environment
are shown in Table 1. The General Population/Uncontrolled MPE is a function of transmit frequency and is
for an exposure period of thirty minutes or less. The MPE limits for persons in an Occupational/Controlled
environment are shown in Table 2. The Occupational MPE is a function of transmit frequency and is for an
exposure period of six minutes or less. The purpose of the analysis described in this report is to determine
the power flux density levels of the earth station in the far-field, near-field, transition region, between the
subreflector or feed and main reflector surface, at the main reflector surface, and between the antenna edge
and the ground and to compare these levels to the specified MPEs.

                Table 1. Limits for General Population/Uncontrolled Exposure (MPE)
                   Frequency Range (MHz)            Power Density (mW/cm2)
                           30-300                                0.2
                          300-1500                    Frequency (MHz)*(0.8/1200)
                        1500-100,000                             1.0

                     Table 2. Limits for Occupational/Controlled Exposure (MPE)
                   Frequency Range (MHz)            Power Density (mW/cm2)
                           30-300                                1.0
                          300-1500                    Frequency (MHz)*(4.0/1200)
                        1500-100,000                             5.0


          Table 3. Formulas and Parameters Used for Determining Power Flux Densities
     Parameter                       Symbol            Formula                    Value           Units
     Antenna Diameter                   D                Input                     3.8            m
     Antenna Surface Area             Asurface          π D2 / 4                  11.34           m2
     Subreflector Diameter             Dsr               Input                     23.7           cm
     Area of Subreflector              Asr              π Dsr 2/4                441.15           cm2
     Frequency                          F                Input                    14000           MHz
     Wavelength                         λ               300 / F                 0.021429          m
     Transmit Power                     P                Input                     8.00           W
     Antenna Gain (dBi)                Ges               Input                     52.4           dBi
     Antenna Gain (factor)              G               10Ges/10                173780.1          n/a
     Pi                                 π              Constant                3.1415927          n/a
     Antenna Efficiency                 η              Gλ2/(π2D2)                  0.56           n/a


                                                                                  Exhibit B
Radiation Hazard Report                                                           Page 2 of 5



1.      Far Field Distance Calculation

The distance to the beginning of the far field can be determined from the following equation:

     Distance to the Far Field Region                       Rff = 0.60 D2 / λ                   (1)
                                                                = 404.3 m

The maximum main beam power density in the far field can be determined from the following
equation:

     On-Axis Power Density in the Far Field                 Sff = G P / (4 π Rff 2)             (2)
                                                                = 0.677 W/m2
                                                                = 0.068 mW/cm2

2.      Near Field Calculation

Power flux density is considered to be at a maximum value throughout the entire length of the
defined Near Field region. The region is contained within a cylindrical volume having the same
diameter as the antenna. Past the boundary of the Near Field region, the power density from the
antenna decreases linearly with respect to increasing distance.

The distance to the end of the Near Field can be determined from the following equation:

     Extent of the Near Field                               Rnf = D2 / (4 λ)                    (3)
                                                                = 168.5 m

The maximum power density in the Near Field can be determined from the following equation:

     Near Field Power Density                               Snf = 16.0 η P / (π D2)             (4)
                                                                = 1.580 W/m2
                                                                = 0.158 mW/cm2

3.      Transition Region Calculation

The Transition region is located between the Near and Far Field regions. The power density
begins to decrease linearly with increasing distance in the Transition region. While the power
density decreases inversely with distance in the Transition region, the power density decreases
inversely with the square of the distance in the Far Field region. The maximum power density in
the Transition region will not exceed that calculated for the Near Field region. The power density
calculated in Section 1 is the highest power density the antenna can produce in any of the regions
away from the antenna. The power density at a distance Rt can be determined from the following
equation:

     Transition Region Power Density                        St = Snf Rnf / Rt                   (5)
                                                               = 0.158 mW/cm2


                                                                              Exhibit B
Radiation Hazard Report                                                       Page 3 of 5



4.      Region between the Main Reflector and the Subreflector

Transmissions from the feed assembly are directed toward the subreflector surface, and are
reflected back toward the main reflector. The most common feed assemblies are waveguide
flanges, horns or subreflectors. The energy between the subreflector and the reflector surfaces
can be calculated by determining the power density at the subreflector surface. This can be
determined from the following equation:

     Power Density at the Subreflector                    Ssr = 4000 P / Asr                (6)
                                                              = 72.538 mW/cm2


5.      Main Reflector Region

The power density in the main reflector is determined in the same manner as the power density at
the subreflector. The area is now the area of the main reflector aperture and can be determined
from the following equation:

     Power Density at the Main Reflector Surface      Ssurface = 4 P / Asurface             (7)
                                                               = 2.822 W/m2
                                                               = 0.282 mW/cm2


6.      Region between the Main Reflector and the Ground

Assuming uniform illumination of the reflector surface, the power density between the antenna and
the ground can be determined from the following equation:

     Power Density between Reflector and Ground           Sg = P / Asurface                 (8)
                                                             = 0.705 W/m2
                                                             = 0.071 mW/cm2


                                                                                  Exhibit B
Radiation Hazard Report                                                           Page 4 of 5



7.     Summary of Calculations

          Table 4. Summary of Expected Radiation levels for Uncontrolled Environment

                                               Calculated Maximum
                                           Radiation Power Density Level
Region                                                (mW/cm2)                 Hazard Assessment
1. Far Field (Rff = 404.3 m)                      Sff       0.068               Satisfies FCC MPE
2. Near Field (Rnf = 168.5 m)                     Snf       0.158               Satisfies FCC MPE
3. Transition Region (Rnf < Rt < Rff)             St        0.158               Satisfies FCC MPE
4. Between Main Reflector and                     Ssr      72.538                Potential Hazard
    Subreflector
5. Main Reflector                                  Ssurface   0.282             Satisfies FCC MPE
6. Between Main Reflector and Ground               Sg         0.071             Satisfies FCC MPE



            Table 5. Summary of Expected Radiation levels for Controlled Environment

                                              Calculated Maximum
                                             Radiation Power Density
Region                                           Level (mW/cm2)                Hazard Assessment
1. Far Field (Rff = 404.3 m)                     Sff       0.068                Satisfies FCC MPE
2. Near Field (Rnf = 168.5 m)                    Snf       0.158                Satisfies FCC MPE
3. Transition Region (Rnf < Rt < Rff)            St        0.158                Satisfies FCC MPE
4. Between Main Reflector and                    Ssr      72.538                 Potential Hazard
    Subreflector
5. Main Reflector                                  Ssurface   0.282             Satisfies FCC MPE
6. Between Main Reflector and Ground               Sg         0.071             Satisfies FCC MPE



It is the applicant's responsibility to ensure that the public and operational personnel are not
exposed to harmful levels of radiation.




8.     Conclusions

Based on the above analysis it is concluded that harmful levels of radiation will not exist in regions
normally occupied by the public or the earth station's operating personnel. The transmitter will be
turned off during antenna maintenance so that the FCC MPE of 5.0 mW/cm2 will be complied with
for those regions with close proximity to the reflector that exceed acceptable levels.


                                                                      Exhibit B
Radiation Hazard Report                                               Page 5 of 5




                            Radiation Hazard Study
                                     Prepared By


                                 COMSEARCH
                    19700 Janelia Farm Boulevard, Ashburn, VA 20147
                    (703)726-5500 http://www.comsearch.com




                                  Jeffrey E. Cowles
                             Principal Frequency Planner

                                DATED: June 1, 2010



Document Created: 2019-04-28 18:37:02
Document Modified: 2019-04-28 18:37:02

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