Question

Overall receiver noise temperature expression if T1, T2… are amplifier 1, 2, and so on noise Temperature and G1, G2, and so on are their gain respectively is_____

(a) T = \(T_1+\frac{T_2}{G_1}+\frac{T_3}{G_1 G_2}+⋯ \)

(b) T = T1+T2 (1-G1)+T3(1-G1G2)+⋯

(c) T = \(T_1+\frac{T_2}{(1-G_1)}+\frac{T_3}{(1-G_1 G_2)}+⋯\)

(d) T = T1+T2 (G1)+T3(G1G2)+⋯

The question was posed to me in an interview for internship.

I need to ask this question from Antenna Noise Temperature in division Antenna Parameters – II of Antennas

Answer 1

Right option is (a) T = \(T_1+\frac{T_2}{G_1}+\frac{T_3}{G_1 G_2}+⋯ \)

To elaborate: Overall receiver noise temperature expression is given by T = \(T_1+\frac{T_2}{G_1}+\frac{T_3}{G_1 G_2}+⋯ \)

System Temperature is one of the important factors to determine the antenna sensitivity and SNR.