Attachment Exhibit A

This document pretains to SES-STA-20190815-01101 for Special Temporal Authority on a Satellite Earth Station filing.

IBFS_SESSTA2019081501101_1849782

Exhibit A Radiation Hazard Report Analysis of Non-Ionizing Radiation for a 1.2 m Earth Station This analysis provides the calculated non-ionizing radiation levels for a 1.2-meter earth station system. The methods and calculations performed in this analysis are based on the FCC Office of Engineering and Technology Bulletin, No.65, October 1985 as 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 (Summarized in Annex 1). There are separate exposure limits applicable to the General Population/Uncontrolled Environment and the Occupational/Controlled Environment. The Maximum Permissible Exposure (MPE) limits for persons in a General Population/Uncontrolled environment for the frequency band of this antenna, is 1 mW/cm2 for a 30 minute or lower time period as shown in Annex 1 (a). The MPE limit for persons in an Occupational/Controlled environment for the frequency band of this antenna is 5 mW/cm2 for a 6 minute time or lower period as shown in Annex 1 (b). The purpose of this analysis described is to determine the power flux density levels of the earth station at the main reflector surface, the near-field, transition region, far-field, between the sub-reflector or feed and, at the main reflector surface, and between the antenna edge and the ground and to compare these levels to the specified MPEs. The parameters of the antenna that is the subject of this analysis are shown in Table 1. Intermediate calculated values and constants are provided in Table 2. Table 1. Input Parameters Used for Determining Power Flux Densities Parameter Symbol Formula Value Units Antenna Diameter D Input 1.2 m Frequency F Input 14125 MHz Transmit Power P Input 8 W Antenna Gain (dBi) Ges Input 43.3 dBi Table 2. Calculated Values and Constants Parameter Symbol Formula Value Units 2 Antenna Surface Area Asurface πD /4 1.13 m^2 Wavelength λ 300/F 0.021239 m Antenna Gain (factor) G 10Ges/10 21379.62 n/a Pi π Constant 3.1415927 n/a Antenna Efficiency η Gλ2 /( π2D2) 0.68 n/a 1

1. Antenna Main Reflector Surface The power density in the main reflector is determined from the Power level and the area of the main reflector aperture. This is determined from the following equation: Power Density at the Main Reflector Surface: Ssurface = 4P/Asurface (1) 2 = 28.294 W/m = 2.829 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 is determined from the following equation: Extent of the Near Field: Rnf = D2 / (4λ) (2) = 16.95 m The maximum power density in the Near Field is determined from the following equation: Near Field Density: Snf = 16.0 η P / (π D2) (3) 2 = 1.920 mW/cm 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 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 is determined from the following equation: Transition Region Power Density: St = Snf Rnf / Rt (4) 2 = 1.920 mW/cm 2

4. Far Field Distance Calculation The distance to the Far Field Region is calculated using the following equation: Distance to Far Field Region: Rff = 0.6 D2 / λ (5) = 40.680 m The maximum main beam power density in the far field is determined from the following equation: On-axis Power Density in the Far Field: Sff = G P / (4 π Rff2) (6) 2 = 0.822 mW/cm 5. Region between the Main Reflector and the Ground Assuming uniform illumination of the reflector surface, the power density between the antenna and the ground is determined from the following equation: Power Density between Reflector and Ground: Sg = P / Asurface (7) 2 = 0.707 mW/cm 3

7. Summary of Calculations Table 3. Summary of Expected Radiation levels for Uncontrolled Environment Calculated Maximum Radiation Hazard Region Symbol Power Assessment Density Level (mW/cm2) Potential 1. Main Reflector Ssurface 2.829 Hazard Potential 2. Near Field (Rnf = 16.95 m) Snf 1.920 Hazard Potential 3. Transition Region (Rnf <Rt< Rff) St 1.920 Hazard Satisfies FCC 4. Far Field (Rff = 40.68 m) Sff 0.822 MPE Satisfies FCC 5. Between Main Reflector and Ground Sg 0.707 MPE Table 4. Summary of Expected Radiation levels for Controlled Environment Calculated Maximum Radiation Hazard Region Symbol Power Assessment Density Level 2 (mW/cm ) Satisfies FCC 1. Main Reflector Ssurface 2.829 MPE Satisfies FCC 2. Near Field (Rnf = 16.95 m) Snf 1.920 MPE Satisfies FCC 3. Transition Region (Rnf <Rt< Rff) St 1.920 MPE Satisfies FCC 4. Far Field (Rff = 40.68 m) Sff 0.822 MPE Satisfies FCC 5. Between Main Reflector and Ground Sg 0.707 MPE It is the applicant’s responsibility to ensure that the public and operational personnel are not exposed to harmful levels of radiation. 4

8. Conclusion Based upon the above analysis, it is concluded that harmful levels of radiation may exist in those regions noted for the Uncontrolled (Table 3) Environment and the Controlled Environment (Table 4). The antenna is located at a facility in Hagerstown, MD. The antenna is in a facility with secured access in and around the proposed antenna. The earth station will be marked with the standard radiation hazard warnings, as well as the area in the vicinity of the earth station to inform those in the general population, who might be working or otherwise present in or near the direct path of the main beam. The applicant will ensure that the main beam of the antenna will be pointed at least one diameter away from any building, or other obstacles in those area that exceed the MPE levels. Since one diameter removed from the center of the main beam the levels are down by at least 20 dB, or by a factor of 100, these potential hazards do not exist for either the public, or for earth station personnel. Finally, the earth station’s operating personnel will not have access to areas that exceed the MPE levels, while the earth station is in operation. The transmitter will be turned off during those periods of 2 maintenance, so that the MPE standard of 5.0 mW/cm will be complied with for those regions in close proximity to the main reflector, which could be occupied by operating personnel. “The licensee shall take all necessary measures to ensure that the antenna does not create potential exposure of humans to radiofrequency radiation in excess of the FCC exposure limits defined in 47 CFR 1.1307(b) and 1.1310 wherever such exposures might occur. Measures must be taken to ensure compliance with limits for both occupational/controlled exposure and for general population/uncontrolled exposure, as defined in these rule sections. Compliance can be accomplished in most cases by appropriate restrictions such as fencing. Requirements for restrictions can be determined by predictions based on calculations, modeling or by field measurements. The FCC's OET Bulletin 65 (available on-line at www.fcc.gov/oet/rfsafety) provides information on predicting exposure levels and on methods for ensuring compliance, including the use of warning and alerting signs and protective equipment for workers.” 5

ANNEX 1 (MPE Levels) a) Limits for General Population/Uncontrolled Exposure (MPE) Frequency Range (MHz) Power Density (mW/cm2) 30-300 0.2 300-1500 Frequency(MHz)*(4.0/1200) 1500-100,000 1 b) Limits for Occupational/Controlled Exposure (MPE) Frequency Range (MHz) Power Density (mW/cm2) 30-300 1 300-1500 Frequency(MHz)*(4.0/1200) 1500-100,000 5 6


Document Created: 2019-08-15 14:09:31
Document Modified: 2019-08-15 14:09:31
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC