Satellite Uplink Calculator
Calculate uplink received power at the satellite transponder input, isotropic received power, and uplink C/N₀.
5
Inputs
Live
Math
3
Related
Enter parameters and click Calculate to view results
Formula & Theory
P_sat = EIRP_earth - FSPL - L_misc + G_sat, (C/N₀)_u = EIRP_earth - FSPL - L_misc + (G/T)_sat + 228.6This formula is used to calculate antenna parameters for satellite uplink calculator.
Overview
Use this satellite uplink calculator to evaluate Earth station uplink EIRP, path loss, received carrier power at the satellite transponder, and uplink carrier-to-noise density (C/N₀)ᵤ.
Input Guide
Enter Earth Station Transmit EIRP, Uplink Path Loss (FSPL), Satellite Antenna Receive Gain, Atmospheric & Misc Losses, Satellite G/T (Optional for C/N₀) exactly in the units shown by this satellite uplink. Check the operating band, unit prefix, and decimal position before calculating; these are the inputs used by the formula.
- Earth Station Transmit EIRP — use dBW.
- Uplink Path Loss (FSPL) — use dB.
- Satellite Antenna Receive Gain — use dBi.
- Atmospheric & Misc Losses — use dB.
- Satellite G/T (Optional for C/N₀) — use dB/K.
Output Guide
The results describe the calculated satellite uplink values for the inputs you entered. Check each value against the available space, selected components, feed system, and operating conditions before making a final design decision.
How This Calculator Works
The Satellite Uplink uses P_sat = EIRP_earth - FSPL - L_misc + G_sat, (C/N₀)_u = EIRP_earth - FSPL - L_misc + (G/T)_sat + 228.6. Supply Earth Station Transmit EIRP (dBW), Uplink Path Loss (FSPL) (dB), Satellite Antenna Receive Gain (dBi), Atmospheric & Misc Losses (dB), Satellite G/T (Optional for C/N₀) (dB/K) in the displayed units, then use the calculated values as the first engineering target for this satellite communication design or analysis.
Design Notes
The uplink power budget determines the signal power arriving at the satellite’s receiving antenna. Earth stations typically use high-power amplifiers (HPAs) and directive dishes to overcome high uplink path loss and ensure the transponder operates within its linear region.
Build and Tuning Notes
When calculating total link performance, the uplink (C/N₀)ᵤ combines with the downlink (C/N₀)₠ using the reciprocal power sum: (C/N₀)ₜₒₜₐₗ⁻¹ = (C/N₀)ᵤ⁻¹ + (C/N₀)₠⁻¹.
Frequently Asked Questions
Why is uplink power higher than downlink power?
Earth stations have access to high electrical grid power and large dish sizes, allowing them to transmit high EIRP (60–85 dBW). Satellites have strict solar array power and weight budgets, limiting their downlink EIRP.
What is Satellite G/T on the uplink?
Satellite G/T (dB/K) is the figure of merit of the satellite’s receive system (receive antenna gain minus system noise temperature in dB-K). Standard GEO satellites have G/T values ranging from -5 dB/K to +15 dB/K.
What is the role of uplink power control (UPC)?
Uplink Power Control automatically increases Earth station transmit power during heavy rain events to compensate for atmospheric attenuation and maintain a constant signal level at the satellite transponder.
Alex Warren
B.Sc. in Electrical & Electronic Engineering (EEE)
Alex specialises in antenna design and wave propagation. His expertise helps ensure these calculators present practical RF concepts, useful design estimates, and clear engineering guidance for students, HAM operators, and wireless professionals.