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# INSAT 4CR - Link Budget for remote DSNG site to the studio.

This page refers to a Ku band satellite new gathering vehicle (DSNG) uplink sending back video to the hub studio site.

 Transponder "gain" input PFD to output EIRP

Uplink SFD = -90 dBW/m^2   single carrier. Note 4 dB input back off
Uplink PFD = - 90 - 4 multi carrier

Occupied bandwidth is 1.4 MHz. Noise bandwidth ofcarrier assumed to be 1/1.2 of this.
So vabdwidth for C/N calvulation = 1.4 MHz /1.2 =  1166666 Hz.

Assuming transponders are 36 MHz wide, with EIRP=51.5 dBW saturated single carrier.
Assuming multicarrier output back off = -2 dB.
EIRP per 1.5 MHz (multicarrier operation) = 51.5 - 2 - 10log(1.5/36) = 35.7 dBW

The transponder 'gain' factor of 143.5 has been adjusted to give +35.7 dBW downlink EIRP for input PFD=-107.8 dBW.

The input figures are adjustable.  You need to overwrite the figures with your own more accurate information and assumptions.

Amend any white boxes and then click the calculate button to obtain results in the green boxes.