Attachment Radiation report

This document pretains to SES-LIC-20120531-00484 for License on a Satellite Earth Station filing.

IBFS_SESLIC2012053100484_953584

smm} Microwave Antenna Radiation Hazards Analysis 16071.1

ANALYSIS OF NON—IONIZING RADIATION O 4.1 M H_STATIO This report analyzes the non— 1on121ng radiation levels for a 4.1 meter earth station. The Office of Engineering and Technology Bulletin, No. 65, Edition 97—01, specifies that there are two separate tiers of exposure limits that are dependent on the situation in which exposure takes place and/or the status of the individuals who are subject to the exposure. The Maximum Permnissible Exposure (MPE) limit for persons in a Uncontrolled/Publlc environment to non—ionizing radiation over a thirty minute period is a power den51ty equal to 1 mW/cm**2 (one milliwatts per centimeter squared). The Maximum Permissible Exposure (MPE) limit for persons in a Controlled/Occupat10nal environment to non—ionizing radiation over a six minute period is a power den51ty equal to 5 mW/cm**2 (five milliwatts per centimeter squared). It is the purpose of this report ts determine the power flux densities of the earth station in the far field, near field, tranSLtlon region, between the subreflector and main reflector surface, at the main reflector surface, and between the antenna edge and the ground. The following parameters were used to calculate the various power flux densities for this earth station: Antenna Diameter, (D) 4.1 meters Antenna surface area, (Sa) pi (D*+*2) / 4 13.20 m**2 Feed Flange Diameter, (Df) = 18.1 cm Area of Feed Flange, (Fa) = pi (Df**2)/ 4 = 257.30 cm**2 Wavelength at 6.1750 GHz, (lambda) = 0.049 meters Transmit Power at Flange, (P) se 80.00 Watts Antenna Gain, (Ges) Antenna Gain at = 3.890E+04 6.1750 GHZz = 45.9 dBi. Converted to a Power Ratio Given By: AntiLog (45.9 / 10) pi, (pi) = 3.1415927 Antenna aperture efficiency, (n) = 0.55 1. Far Field Calculations The distance to the beginning of the far field region can be found by the following equation: (1) Distance to the Far Field Region, (Rf) 0.60(D**2) / lambda 207.6 m (1) Federal Communications Commission, Office of Engineering & Technology, Bulletin No. 65, pp. 17 & 18. l

The maximum main beam power density in the far field can be calculated as follows: (1) On—Axis Power Density in the Far Field, (Wf) = GES P 4§pij%Ré*¥§) s 5.75 W/m**2 = 0.57 mW/cm**2 2. Near Field Calculation Power flux density is considered to be at a maximum value throughout the entire length of the defined region. The region is contained within a cylindrical volume having the same diameter as the antenna. Past the extent of the near field region the power density decreases with distance from the transmitting antenna. The distance to the end of the near field can be determined by the following equation: (1) Extent of near field, (Rn) = D**2 / 4(lambda) = 86.50 m The maximum power density in the near field is determined by: (1) Near field Power Density, (Wn) = 16.0(n)P mW/cm**2 pi(D**2) 13.33 W/m**2 II = 1.33 mW/cm**2 3. Transition Region Calculations The transition region is located between the near and far field regions. As stated above, the power density begins to decrease with 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 in the near field region, as shown above, will not exceed 1.33 mW/cm**2. (1) IBID

4. Region Between Feed Flange and Reflector Transmissions from the feed horn are directed toward the reflector surface, and are confined within a conical shape defined by the feed. The energy between the feed and reflector surface can be calculated by determining the power density at the feed flange. This can be accomplished as follows: Power Density at Feed Flange, (Wf) 2(P) / Fa 621.83 mW/cm**2 5. Main Reflector Region The power density in the main reflector region is determined in the same manner as the power density at the feed flange, above, but the area is now the area of the reflector aperture: Power Density at Reflector Surface, (Ws) (2(P) / Sa) 12.12 W/m**2 1.21 mW/cm**2 6. Region between Reflector and Ground Assuming uniform illumination of the reflector surface, the power density between the antenna and ground can be calculated as follows: Power density between Reflector and Ground, (Wg) = (P / Sa) = 6.06 W/m**2 0.61 mW/cm**2

Table 1 Summary of Expected Radiation Levels Based on (5 mW/cm**2) MPE for Controlled Environment Calculated Maximum Region Radiation Level (mW/cm**2) Hazard Assessment 1. Far Field, (Rf)= 207.6 m 0 .57 SATISFIES ANSI 2. Near Field, (Rn)= 86.50 m 1. 33 SATISFIES ANSI 3. Transition Region, (Rt) 1. 33 SATISFIES ANSI Rn < Rt < Rf 4. Between Reflector 621.853 POTENTIAL HAZARD and feed 5. Reflector Surface 1.231 SATISFIES ANSI 6. Between Antenna 0 .61 SATISFIES ANSI and Ground It is the applicants responsibility to ensure that the public and operational personnel are not exposed to harmful levels of radiation.

Table 2 Summary of Expected Radiation Levels Based on (1 mW/cm**2) MPE for Uncontrolled Environment Calculated Maximunm Region Radiation Level (mW/cm**2) Hazard Assessment 1. Far Field, (Rf)= 207.6 m 0 .57 SATISFIES ANSI 2. Near Field, (Rn)= 86.50 m 1.33 POTENTIAL HAZARD 3. Transition Region, (Rt) 1. 33 POTENTIAL HAZARD Rn < Rt < Rf 4. Between Reflector 621.83 POTENTIAL HAZARD and feed 5. Reflector Surface 1.21 POTENTIAL HAZARD 6. Between Antenna 0.61 SATISFIES ANSI and Ground It is the applicants responsibility to ensure that the public and operational personnel are not exposed to harmful levels of radiation.

EXHIBIT B RADIATION HAZARD STUDY


Document Created: 2012-04-17 16:39:42
Document Modified: 2012-04-17 16:39:42
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC