DVB Downlinkbudgett calculator

Satellite&Transponder
Satellite Position	equals West	Degrees
Uplink Carrier to noise (C+N/N)		dB
Satellite txp. Carrier to co-channel interference (C/Ico)		dB
Satellite txp. Carrier to intermodulation (C/Iim)		dBW/4kHz
Location
Latitude	Degminsec
Longitude	Degminsec
Azimuth		Degrees
Elevation		Degrees
Slant Range		km
Satellite delay (Up+Downlink)		ms
Antenna Diameter		Meter
Antenna Efficiency		%
Antenna Gain		dBi
Antenna Noise Temperature		Kelvin
LNB Noise Figure		dB
LNB Input VSWR	1:
Waveguide loss		dB
Polarizer loss		dB
System Noise Temperature		Kelvin
G/Tsys		dB/Kelvin
Rx Frequency		MHz
IF frequency (Universal LNB swo 11700MHz)		MHz
Downlink EIRP (from footprint)		dBW
Free Space Path Loss		dB
Atmospheric loss		dB
Symbolrate		kBaud
FEC
DVB-S2 Pilot
DVB-S2 Frame
Information Capacity (Netto Bitrate)		kBit/s
Theoretical Information Capacity(Shannon limit)		kBbit/s
Coding efficiency based on Shannon limit		%
Modulator Rolloff
Occupied Bandwidth		MHz
Allocated Bandwidth		MHz
C/No		dBHz
C/N Occupied Bandwidth		dB
Eb/No Nettobitrate ( TS payload bitrate)		dB
C+N/N		dB
C/N		dB
Eb/No datarate		dB
Eb/No Transmission rate		dB
Eb/No Margin		dB ( +6dB is recommended)

The C/Iim and C/Ico values for Intelsat transponders can be found in IESS 410e table 1a page17 and table 2b page21.
The default C/Iim and C/Ico values are typical for Intelsat VIIA series Ku-spot beam in multicarrier mode.
For satellites with one carrier pr. transponder the typical values could be C/Iim =-30dBW/4kHz and C/Ico =40dBW/4kHz.

For Intelsat VII series satellites Ku-band the values are C/Iim =-16dBW/4kHz and C/Ico =20.5dBW/4kHz.
This are worst case values for multicarrier transponders.

Use the calculated values as a indication only and be sure there is a recommended 6dB downlink margin.

Receiver Input Level Calculation

Power reaching Antenna	dBW
Power flux density at earthstation	dBW/M^2
LNB input power	dBW
LNB Gain	dB
LNB output power	dBmW
Cable loss	dB/100 meters ( Click on the table below)
Coax cable length	m
Coax cable loss	dB
Demodulator maximum power	dBmW
Demodulator minimum power	dBmW
Demodulator Input Power	dBmW
Agilent E4402B S/A Measured Input Noise Density	dBm/Hz
Demodulator Input Noise Density	dBm/Hz
Demodulator Input Level 75ohm	dBuV@75ohm RMS
Demodulator Input Level 50ohm	dBuV@50ohm RMS

White cells are outputvalues

Most receivers are specified to work between -30dBmW to -60dBmW.

Be aware that increasing the level won't help if the received carrier to noise is too low ( i.e. antenna too small).

Cable loss for some common cables - Click on the value you want to use !

Cable type	100MHz	200MHz	500MHz	900MHz	1450MHz	1750MHz	2050MHz
RG179	32.0dB	47.0dB	65.0dB	100.0dB	125.0dB	141.0dB	158.0dB
RG59/U	8.5dB	13.1dB	21.3dB	29.5dB	39.0dB	44.6dB	50.2dB
RG6/U	6.9dB	10.2dB	16.4dB	22.6dB	29.8dB	34.1dB	38.4dB
RG11/U	4.9dB	7.2dB	12.1dB	17.1dB	22.6dB	25.9dB	29.2dB

Threshold Eb/No as specified by ETS 300 421

FEC	Eb/No[dB]	Calculated[dB]
1/2	4.5
2/3	5.0
3/4	5.5
5/6	6.0
7/8	6.4
1	9.0