ND SatCom SKYWAN IDU 7000, Manual

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86 Network Design and Engineering Guide 2010-10-26
Outdoor Unit and Satellite Link Design
SkyWAN
®
Link Budget Calculation Tool
3.5.1 Satellite Data Worksheets (Ku- and C-Band)
The tool contains a satellite data sheets for defining C-Band and Ku-Band transponder.
Figure 3-11 Link Budget Tool - Satellite Data Worksheet(s)
For C-Band transponders the link polarization (circular/linear/unknown) must be specified,
whereas the for Ku-Band linear polarization is assumed. The intermodulation parameters I0 up/
down allow to specify signal degradation due to intermodulation on the up- and downlink. The
default settings -300/-200 dBW/Hz describe a situation without intermodulation effects. If no
detailed information about transponder intermodulation is available a typical way to estimate
this effect is:
- Increase I0 up until the power requirement for the earth stations is increased by 20%.
- Increase I0 down until the power requirement for the earth stations is increased by addi-
tional 5%.
From the transponder data saturation, G/T, SFD, Input Back-Off and Output Back-Off the sat-
ellite gain is calculated. Note that these values refer to the center of the satellite beam. The
transponder bandwidth is needed to calculate the PEB.