Topic: Communication Systems
For a satellite transponder with a receiver antenna gain of 12 dB, an LNA gain of 10 dB, and equivalent noise temperature of 26 $dBK^{-1}$, the $G/Te$ is
- A. $4~dBK^{-1}$
- B. $-4~dBK^{-1}$
- C. $26~dBK^{-1}$
- D. $-26~dBK^{-1}$
Answer: B. $-4~dBK^{-1}$
Explanation: The total gain $G$ is the sum of antenna gain and LNA gain in dB. $G = 12 + 10 = 22~dB$. $\frac{G}{T}=(G)_{dB}-T(dBK^{-1}) = (22-26)dBK^{-1} = -4~dBK^{-1}$.