Given an amplifier with an output power of 15 W and an input

Given an amplifier with an output power of 1.5 W and an input power of 75 mW, compute the following: The relative power gain as a ratio, A_p. The relative power gain in decibels, A_P (dB).

Solution

Given

Input power to an amplifier is P_in = 75 mW

Output power to an amplifier is P_out = 1.5 W

a) Relative power gain A_p = P_out/P_in = 1.5 / (75*10^-3) = 20

b) Relative power gain in decibels is AP(dB) = 10 log₁₀(A_P) = 10 * log₁₀(20) = 13.01 dB