Link Budget Calculator
Calculators / RF Link Budget
RF Link Budget
Calculator
Complete end-to-end RF link budget: EIRP → free-space path loss → received power → SNR → link margin. Essential for wireless communication system design, satellite link analysis, and RF system planning. Full waterfall budget breakdown.
⚙ Link Budget Engine
20 dBm = 100 mW
0 dBi = isotropic. Half-wave dipole = 2.15 dBi
EIRP = Pt + Gt − cable = —
Antenna beam misalignment loss
λ = — cm
Free-space link distance
Total atm loss = rate × distance
0 dBi = isotropic. High-gain dish: 30–50 dBi.
Coax run from antenna to receiver
Minimum detectable signal level
LNA: 2–4 dB, typical receiver: 6–10 dB
Advanced / SNR Parameters
Used for thermal noise floor calculation
Minimum Eb/N0 for target BER
Hardware non-idealities, modem imperfections
Design target fade margin (typical: 10–20 dB)
Link Budget Summary
Complete Link Budget Waterfall
| # | Parameter | Value (dB) | Running Total (dBm) | Note |
|---|---|---|---|---|
| Enter values above to generate budget | ||||
📖 Theory
A link budget is an accounting of all gains and losses in an RF communication system from the transmitter output to the receiver decision circuit.
Budget Equation
Pr = Pt + Gt − L_t − FSPL − L_atm − L_pol + Gr − L_r
All in dB/dBm. Every gain adds, every loss subtracts.
Link Margin
M = Pr − S
M = Pr − (N₀ + NF + BW + Req_SNR)
M > 0 → link works. Design for M ≥ 10–20 dB.
FSPL Formula
FSPL(dB) = 20·log(d_km) + 20·log(f_GHz) + 92.44
📊 Received Power & Margin Viewer
Link Budget Insights
Enter link parameters to see system design insights.
Common Applications
Wireless Communication
Design WiFi, cellular, LoRa, ZigBee, and Bluetooth links. Determine maximum range and required antenna gain for a given link margin.
Satellite Links
LEO, MEO, and GEO satellite uplink/downlink budgets. Calculate EIRP, G/T, and C/N₀ for earth station and spacecraft design.
RF System Planning
Network coverage planning, base station siting, repeater spacing, and spectrum efficiency analysis for licensed and unlicensed bands.
Research & Education
Teach and study wireless propagation, link margin concepts, modulation-SNR requirements, and noise figure effects on system performance.
