Attachment RF Hazard

This document pretains to SES-MOD-20110214-00152 for Modification on a Satellite Earth Station filing.

IBFS_SESMOD2011021400152_868453

RF RADIATION HAZARD ANALYSIS Exhibit #B Antenna Diameter, (D) = 1.5 meters / 4.9215 Feet Antenna Surface Area (Sa) = 1.7671 sq meters Subreflector Diameter (Ds) = 0.0000 centimeters Ku Wavelength at 14.250 GHz (LAMBDA) = 0.0211 meters Power output of VPC Flange= 25.563 dB Path Loss to OMT (IL) = 3 dB Power at OMT, (P) = 180.43 Watts Antenna Gain at 14.250GHz (G) = 45.90 dBi (2 port antenna gain) Antenna Gain given in Power Ration, (Ges) = 3.89E+04 Antenna Aperture Efficiency (N) = 0.650 Region Radition Level Hazard Assessment Far Field, (Rf) = 63.981 meters / 209.92 Feet 13.646 mW/cm sq Potential Hazard Near Field, (Wf) = 26.659 meters / 87.467 Feet 26.546 mW/cm sq Potential Hazard Transition Region (Rt) equal to or less than Ru<Rt<Rf 26.546 mW/cm sq Potential Hazard Between Main Reflector N/A (no subreflector) and Subreflector (Ws) Main Reflector Region (Wm) 20.420 mW/cm sq Potential Hazard Power Density Between Reflector 10.210 mW/cm sq Potential Hazard and Ground Far Field Off Axis (WF) 0.136 mW/cm sq Potential Hazard Near Field Off Axis (WN) 0.265 mW/cm sq Potential Hazard Conclusion: Based on the above analysis, harmful areas of Radiation do exist in the 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 1mW cm sq. becuase the antenna is mounted on top of the truck, which is at least 8 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 (20dB) 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 ensure 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 ladder that is not accessible by the general public. Note: See Exhibit #Ba for how the above calculations were made.

Exhibit Ba Analysis on Non-Ionizing Radiation Antenna Diameter, (D) = D: = 1.5 meters D*3.281 = 4.922 Feet Antenna Surface Area, (Sa) = Sa: = p* D*D Sa = 1.767 sq meters 4 Subreflector Diameter, (Ds) = Ds: = 0 cm Ds*.3937 0.000 Inches Ds*Ds Area of Subreflector, (As) = As: = p* As= 0.000 sq meters 4 Center Frequency, (Cf) = Cf: = 14.250 GHz Wavelength at (Cf), (Lambda) = Lambda = 0.0211 meters C-Band = .049 Ku-Band = .0211 Tansmit Power at HPA or VPC Flange, (P1) = P1= 360.00 watts P2:=log(p1)*10 P2= 25.563 dB Path Loss from HPA or VPC to OMT, (IL) = Loss: = 3 P3:= P2-Loss P3= 22.563 OMT Pwr in dB P3 P:= 10 P= 180.427 OMT Pwr in watts 10 Antenna Gain at (Cf), (Gain) = Gain: = 45.90 dBi Gain Antenna Gain Converted to Power Ratio (Ges)= Ges: = 10 Ges = 3.89E+04 Ratio 10 Antenna Aperture Efficiency, (n) = n: = 0.6500 .60 * (D*D) Rf = 63.981 meters Far Field (Rf) = Rf= Lambda Rf*3.281= 209.922 feet Ges*P Far Field Power Density (Wf) = Wf= * .1 Wf = 13.646 mw sq cm 4* p * (Rf*Rf) (D*D) Rn= 26.659 meters Near Field (Rn) = Rn= 4*Lambda Rf*3.281= 87.467 feet 16*n*P Near Field Power Density (Wn) = Wn= * .1 Wn = 26.546 mw sq cm p* (D*D) mw sq cm Transition Region (Rt) = Rt = Wn*1 Rt= 26.546 (Equal to or less than) 2*P Pwr Density at Sub Reflector (Ws) = Ws= *1000 Ws = N/A As Main Reflector Region Pwr Density (Wm) = Wm= 2*P *.1 Wm = 20.420 mw sq cm Sa Pwr Density between main reflector and P Wg= *.1 Wg = 10.210 mw sq cm ground (Wg) = Sa Far Field Off Axis (WF) = WF:= Wf*.01 WF = 0.136 mw sq cm Near Field Off Axis (WN) = WN:= Wn*.01 WN = 0.265 mw sq cm


Document Created: 2011-02-11 13:09:09
Document Modified: 2011-02-11 13:09:09
© 2025 FCC.report
This site is not affiliated with or endorsed by the FCC