Attachment GE Healthcare ES-RAD

This document pretains to SES-LIC-20050624-00812 for License on a Satellite Earth Station filing.

IBFS_SESLIC2005062400812_435149

RADIATION HAZARD ANALYSIS Exhibit A Studies were conducted to predict radiation levels around the proposed earth station. The level of RF radiation calculated below has been compared to a maximum safe level of 5 mW per square cm as defined by OET Bulletin No. 65 (August 1997). Antenna main beam gain (G) = 56.5 (dBi) Power into feed (P) = 162 (watts) Antenna diameter (D) = 6.1 (meter) Wavelength (h) = .0214 (meter) Frequency (f) = 14.000 (GHz) Efficiency (n) = 0.65 NEAR FIELD RADIATION The extent of the near field can be described by the equation: WHERE: R = D2 R = Extent of near-field 4h D = Antenna diameter h = Wavelength R = 6.12 = 434.7 meters 4 (.0214) The maximum value of the near field on-axis (main beam) power density is given by the equation: WHERE: S = 16 np S = Maximum near-field power density. 2 πD n = Aperture efficiency p = Power into feed D = Antenna diameter 16 (.65) (162) = 14.41 W/m2 or 1.44 mW/cm2 π (6.1)2 FAR FIELD RADIATION The distance to the beginning of the far field region can be expressed by the equation: WHERE: 2 R = 0.6D R = Distance to beginning of far field h D = Antenna diameter h = Wavelength .60 (6.1)2 = 1043.3 meters .0214

Exhibit B Page 2 of 4 TRANSITION REGION On-axis power density will decrease inversely with distance in the transition region. The power density can be expressed by the equation. WHERE: S = S(nf) R(nf) S = Power density R S(nf) = Maximum power density for near field R(nf) = Extent of near field R = Distance to point of interest At the beginning of the transition region, i.e., at a distance of 434.7 meters, the power density is: S = 1.44 (434.7) = 1.44 mW/cm2 434.7 At the beginning of the far field, i.e., at a distance of 1043.3 meters, the power density is: S = 1.44 (434.7) = 0.6 mW/cm2 1043.3 WITHIN ANTENNA The maximum power density between the main reflector and subreflector is taken as the power density at the subreflector. This can be described from the equation: WHERE: S = P S = Power density πr2 P = Power into feed r = Radius of subreflector (cm) S = 162 = 0.1719 W/cm2 = 171.9 mW/cm2 π (17.32)2 The power density at the reflector is expressed by the equation: WHERE: S = P S = Power density πr2 P = Power into feed r = Radius of reflector S = 162 = 5.54 W/m2 = 0.55 mW/cm2 π (3.05)2

Exhibit B Page 3 of 4 BETWEEN ANTENNA AND GROUND As suggested by OET Bulletin 65, Edition 97-01 (August 1997) the level of RF fields in the off- axis vicinity of aperture antennas may be estimated by use of the specifications for maximum allowable gain for antenna sidelobes not within the plane of the Geostationary Orbit, as follows: 32 - {25 log10(0)} dBi for 1°≤ 0 ≤ 48° and: -10 dBi for 48°< 0 ≤180° WHERE: 0 = the angle in degrees from the axis of the main lobe dBi = dB relative to an isotropic radiator Therefore, utilizing a value of -10 dBi for sidelobe gain at all vicinities on the ground near the antenna and equation (18) for far field power density, S = P(-10 dBi) where S = Power Density 4π R2 P = Power Into Feed R = Distance from Feed to Ground S= 162 (0.1) = 0.054 W/m2 = 0.0054 mW/cm2 4π(4.9)2

Exhibit B Page 4 of 4 Summary Table Region Radiation Level Hazard Assessment (mW/cm2) Far Field, Rf = 1043.3m 0.6 Complies with Guidelines Near Field, Rn = 434.7m 1.44 Complies with Guidelines Transition Region, Rt <1.44 Complies with Guidelines Rn < Rt < Rf Between Main Reflector and 171.9 Potential Hazard Subreflector Reflector Surface 0.55 Complies with Guidelines Between Antenna and 0.0054 Complies with Guidelines Ground CONCLUSION: 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 earth station will be marked with the standard radiation hazard warnings, on the antenna itself, warning personnel to avoid the area in front of the reflector when the transmitter is operational. To ensure compliance with the safety limits, the earth station transmitter will be turned off whenever maintenance and repair personnel are required to work in an area where the radiation level exceeds the level recommended by applicable guidelines. Additionally, the earth station is secured and access is controlled. 12/04


Document Created: 2005-06-07 10:36:01
Document Modified: 2005-06-07 10:36:01
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