Noise Floor Calculator (kTB + NF)

Compute receiver noise floor from bandwidth, noise figure and temperature using the classic kTB relation. Optionally, evaluate SNR for a given signal level.

Inputs & Results

Noise Figure (NF, dB) Equivalent Noise Bandwidth

Physical Temperature (K) Implementation / margin (dB) Optional: Signal level to evaluate SNR (dBm)

Results will appear here.

RX Block Diagram & Theory

Static Receiver Front-End Diagram

Key Equations

kTB (W) = k · T · B

N₀ (dBm/Hz) ≈ −174 dBm/Hz + 10·log₁₀(T/290)

N_ideal (dBm) = N₀ + 10·log₁₀(B_Hz)

N_system (dBm) = N_ideal + NF (dB) + margin

The noise figure NF represents how much additional noise the receiver front-end adds beyond the thermal noise floor set by kTB. For a given signal power P_sig, SNR at the detector is simply P_sig − N_system (in dB).