Build a first-order satellite power link budget using spacecraft EIRP, propagation loss, receive antenna gain, implementation losses, and receiver threshold. The result shows received carrier power and link margin in decibels, making it easy to identify whether antenna, power, range, or receiver performance needs further refinement.
Positive margin indicates that the estimated carrier power is above the entered receiver threshold. Negative margin quantifies the additional gain, EIRP, or loss reduction required.
A full digital link analysis usually derives threshold from C/N₀, Eᵦ/N₀, bandwidth, data rate, coding, and noise temperature. Enter a compatible threshold.
With 20 dBW EIRP, 190 dB path loss, 45 dBi receive gain, 3 dB implementation loss, and a −125 dBW threshold, received power is −128 dBW and link margin is −3 dB.
No. EIRP combines transmitter output, feed losses as applicable, and antenna gain in the link direction.
Either field can hold it if your accounting is consistent and the loss is included exactly once.
Received carrier power is below the entered receiver threshold; the magnitude shows the estimated shortfall in decibels.
No. Convert all absolute power values to dBW before using this calculator; gains and losses remain in dB.
No. Availability also depends on fading distributions, interference, hardware reliability, pointing, and operational assumptions.
| Input | Unit | Role |
|---|---|---|
| Spacecraft EIRP | dBW | Transmitter power plus transmit antenna gain. |
| Propagation path loss | dB | Free-space and modeled propagation loss. |
| Receive antenna gain | dBi | Ground or user-terminal antenna gain. |
| Implementation losses | dB | Pointing, cable, polarization, atmosphere, and hardware. |
| Receiver threshold | dBW | Required carrier power for the selected service. |