Topic: Communications
The noise figure of a device is 2. If input SNR is 37 dB, what would be output SNR?
- A. 18.5 dB
- B. 34 dB
- C. 40 dB
- D. 74 dB
Answer: B. 34 dB
Explanation: Noise figure = 2. Noise figure (in dB) = 10 log_10 (2) = 3 dB. Noise figure (NF) = (S/N)_input / (S/N)_output. ∴ NF (in dB) = (S/N)_input,dB - (S/N)_output,dB. So, (S/N)_output,dB = 37 - 3 = 34 dB.