Calculateur d'Affaiblissement en Espace Libre — Formule

RF Power in dBm

Formulas

dBm = 10 x log10(P_mW)

V_rms = sqrt(P x Z)

dBm is decibels relative to 1 milliwatt. Common values: 0 dBm = 1 mW, 10 dBm = 10 mW, 20 dBm = 100 mW, 30 dBm = 1 W.

Exemple Résolu

100 mW transmitter into 50 ohm system.

  1. dBm = 10 x log10(100) = 20 dBm
  2. Power = 100 / 1000 = 0.1 W
  3. V_rms = sqrt(0.1 x 50) x 1000 = 2236 mV