Parameters
Presets
TX Power P_t
20.0 dBm
Frequency f
2400 MHz
Distance d
1.00 km
TX Antenna Gain G_t
3.0 dBi
RX Antenna Gain G_r
3.0 dBi
Noise Figure NF
5.0 dB
Bandwidth BW
20.0 MHz
Misc Losses L_misc
3.0 dB
Rain Fade (ITU-R)
0.0 dB
Modulation
Target BER
—
Received Power P_r [dBm]
—
SNR [dB]
—
Link Margin M [dB]
—
Max Range [km]
Friis Transmission Equation
$$P_r = P_t + G_t + G_r - L_{fs} - L_{misc} \quad \text{[dBm]}$$ $$L_{fs} = 20\log_{10}\!\left(\frac{4\pi d}{\lambda}\right) = 20\log d + 20\log f - 147.55 \;\text{[dB]}$$ $$N_{floor} = -174 + NF + 10\log_{10}(BW) \quad \text{[dBm]}$$ $$SNR = P_r - N_{floor}, \quad M = SNR - SNR_{req}$$
Engineering note: Antenna gain values G_t and G_r obtained from FDTD or MoM electromagnetic simulations can be fed directly into this calculator for system-level link budget verification. Applicable to satellite, 5G, radar, and IoT link design.