An attenuator with loss L» 1 is followed by an amplifier with noise figure F and gain Ga = 1 /L.
(a) Find the noise figure of the cascade at tempera true T0.
(b) Consider the cascade of two identical attenuator- amplifier stages as in part (a). Determine the noise figure of the cascade at temperature T0.
(c) Generalize these results to N identical attenuators and amplifiers at temperature T0. How many decibels does the noise figure increase as a result of doubling the number of attenuators and amplifiers?
