Satellite Link Budget Calculator

Calculate complete uplink and downlink budgets for satellite communications.

Satellite Parameters

Ground Station (Uplink)

Ground Station (Downlink)

Link Parameters

Satellite Band Reference

Band Uplink Downlink Notes
L-band1.6 GHz1.5 GHzMobile, MSS
S-band2.0 GHz2.2 GHzMobile
C-band6 GHz4 GHzLow rain fade
Ku-band14 GHz12 GHzDTH, VSAT
Ka-band30 GHz20 GHzHTS, high capacity
V-band50 GHz40 GHzFuture HTS

Satellite Link Budget Theory

Downlink C/N

C/N = EIRP - FSPL + G/T - k - 10*log10(B)
EIRP in dBW, FSPL in dB, G/T in dB/K, k = -228.6 dBW/K/Hz

The carrier-to-noise ratio determines link quality. Both uplink and downlink C/N must exceed the threshold for reliable communications.

Key Parameters

  • G/T: Figure of merit (gain/noise temperature)
  • EIRP: Effective radiated power
  • FSPL: Free space path loss
  • Eb/N0: Energy per bit to noise (for digital)