If the input signal power to a communication system is 1 W and the output power is 1 mW, the system attenuation is:
If the input signal power to a communication system is 1 W and the output power is 1 mW, the system attenuation is:
The attenuation of a system is calculated using the formula: Attenuation (dB) = 10 * log10(Pi / Po), where Pi is the input power and Po is the output power. Given Pi is 1 W and Po is 1 mW (which is 0.001 W), the calculation becomes: Attenuation = 10 * log10(1 / 0.001) = 10 * log10(1000) = 10 * 3 = 30 dB.
Attenuation (A) = 10 log(Pi / Po) Pi=Input power, Po = output power. A= 10 x log (1W/1mW) = 10 x log(1000) = 10 x 3 = 30 dB
From Pg 1-55 equation below should be used for signal in Watts. dB = -10log( P out/P in) = -10log(0.001W/1W) = ±10log(0.001) = ±10(-3) =30