Attachment comcast-Exhibit B.pd

This document pretains to SES-LIC-20050315-00320 for License on a Satellite Earth Station filing.

IBFS_SESLIC2005031500320_421863

RF RADIATION HAZARD ANALYSIS Exhibit #B Antenna Dia. (D)=1.5 Meters 4.922 Feet Antenna Surface Area (SA)=1.767 sq meters Subreflector Dia. (DS)=N/A (prime focus offset) Subreflector Surface Area (AS)=N/A KU Wavelength at 14.250 GHz (LAMBDA)=.0211 meters Power at output of HPA flange=20.969 dB Path Loss to OMT (IL)=.6 dB Power at OMT Flange (P)=130.645 watts Antenna Gain at 14.250 GHz (G)=45.9 dBi (2 port antenna gain) Antenna Gain given in Power Ratio (GES)=3.89E+04 Antenna Aperture Efficiency (N)=.7764 Region Radiation Level Hazard Assessment Far Field (Rf) 63.981 m 209.922 ft 9.88 mW/cm sq Potential Hazard Near Field (Wf) 26.659m 87.467 ft 22.96 mW/cm sq Potential Hazard Transition Region (Rt) equal to or less than Potential Hazard Ru<Rt<Rf 22.96 mW/cm sq Between Main Reflector and N/A (no subreflector) Subreflector (Ws) Main Reflector Region (Wm) 14.3786 mW/cm sq Potential Hazard Power Density Between Reflector 7.393 mW/cm sq Potential Hazard and Ground Far Field Off Axis (WF) .099 mW/cm sq Meets ANSI Requirements Near Field Off Axis (WN) .23 mW/cm sq Meets ANSI Requirements Conclusion: Based on the above analysis, harmful areas of Radiation do exist in areas around the antenna and in the path of the antenna toward the satellite that it is pointed at. The Area occupied by the general public will not exceed the ANSI limit of 1 mW cm sq. because the antenna is mounted on top of the truck, which is at least 10 feet above the ground, and safety increases with look angles used by the Satellites in the United States on Dom. Sat. arch. The areas on the ground and behind the antenna are 100 times less power (20 dB) when at a min. of the dia. of the reflector, this is reflected in the Off Axis figures as seen above (WF) & (WN). The SNG will be marked with the standard radiation hazard warnings, and on the antenna itself. The warning signs will warn personnel to avoid the area around and in front of the reflector when the transmitter is operating. To ensure compliance with safety limits, the earth station transmitter will be turned off and marked to remain off whenever maintenance and repair personnel are required to work in the areas of potential hazard as defined in the above study. Additionally the earth station personnel will be trained to insure that the antenna path is clear at all times while the transmitter is in operation. The only access to the roof of the truck, is a stored ladder which will only be used when the transmitter is off and not accessible by the general public. Note: See Exhibit #Ba for how the above calculations were made.

Exhibit Ba Analysis of Non-Ionizing Radiation Antenna Diameter, (D)=.................................. D 1.5 meters D. 3.281 = 4.922 Feet D. D Antenna Surface Area, (Sa)= ........................ Sa π. Sa = 1.767 sq meters 4 Subreflector Diameter, (Ds)=.......................... Ds 0 cm Ds . .3937 = 0 Inch's Ds . Ds Area of Subreflector, (As)=............................. As π. As = 0 sq cm 4 Center Frequency, (Cf)=................................. CF 14.250 GHz Wavelenght at (Cf), (Lambda)=....................... Lambda .0211 meters C-Band=.049 Ku-Band=.0211 Transmit Power at HPA or VPC Flange, (P1)=.. P1 150 watts P2 log( P1) . 10 P2 = 21.761 dB Path Loss from HPA or VPC to OMT, (Loss)=.. Loss .6 dB P3 P2 Loss P3 = 21.161 OMT Pwr in dB Power at OMT, (P)=....................................... P3 10 P 10 P = 130.645 OMT Pwr in watts Antenna Gain at (Cf), (Gain)=.......................... Gain 45.9 dBi Gain Antenna Gain Converted to Power Ratio, (Ges). Ges 10 10 Ges = 3.89 10 4 Ratio Antenna Aperture Efficiency, (n)=..................... n .7764 _________________________________________________________________________________ .60. ( D. D ) Far Field (Rf)= Rf Rf = 63.981 meters Rf. 3.281 = 209.922 Feet Lambda Ges. P . Far Field Pwr Density (Wf)= Wf .1 Wf = 9.88 mw sq cm 4. π . ( Rf. Rf) D. D Near Field (Rn)= Rn Rn = 26.659 meters Rn. 3.281 = 87.467 Feet 4. Lambda 16. n . P . Near Field Pwr Density (Wn)= Wn .1 Wn = 22.96 mw sq cm π . ( D. D ) Transition Region (Rt)= Rt Wn . 1 Rt = 22.96 mw sq cm (Equal to or less then) Pwr Density at Sub Reflector (Ws)= (N/A No Sub Reflector) 2. P . Main Reflector Region Pwr Density (Wm)= Wm .1 Wm = 14.786 mw sq cm Sa P. Pwr Density between main reflector and ground (Wg)= Wg .1 Wg = 7.393 mw sq cm Sa Far Field Off Axis (WF)= WF Wf. .01 WF = 0.099 mw sq cm Near Field Off Axis (WN)= WN Wn . .01 WN = 0.23 mw sq cm


Document Created: 2005-01-31 12:40:58
Document Modified: 2005-01-31 12:40:58
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