RF Link Budget Calculator — Receive Power & Fade Margin | RFCalcLab
Design reliable wireless links with our link budget tool. Calculate received signal strength (RSSI) and fade margin to ensure link stability against environmental factors like rain fade and multipath.
How to Use the RF Link Budget Calculator
Input your transmitter power, antenna gains, and cable losses for both ends of the link. Don't forget to include a fade margin to account for environmental fluctuations.
The calculator determines the received power (Prx) and compares it to your receiver sensitivity. A positive fade margin indicates the link is likely to remain stable.
Adjust antenna height or gain if the fade margin is too low. Typical reliable links aim for at least 10–20 dB of fade margin depending on the required uptime (99.9% or 99.99%).
Related Topics
- link budget calculator
- RF link budget
- fade margin
- receive power
- antenna gain
- RSSI
- Friis equation
Frequently Asked Questions
- What is a Link Budget?
- A link budget is the accounting of all gains and losses from the transmitter, through the medium (free space, cable, air), to the receiver in a telecommunication system.
- Why is Fade Margin important?
- Fade margin is 'extra' signal strength added to the link to account for unpredictable variables like rain, atmospheric changes, or moving obstacles that might temporarily weaken the signal.
- How do I improve my link budget?
- You can improve a link budget by increasing transmitter power, using higher-gain antennas, reducing cable lengths and losses, or switching to a more sensitive receiver.