As an experienced technician， you are responsible for Technical Support. A customer calls to askthe best signal level and noise level for cell phone. How to respond？（）
A: -40dBm signal and -90dBm noise
B: -50dBm signal and -90dBm noise
C: -30dBm signal and -90dBm noise
D: -20dBm signal and -90dBm noise
A: -40dBm signal and -90dBm noise
B: -50dBm signal and -90dBm noise
C: -30dBm signal and -90dBm noise
D: -20dBm signal and -90dBm noise
举一反三
- In the OSNR model for EDFA amplifiers， SNR OUT = 1/（1/SNR IN + FhvB/P IN ）， what does SNR IN represent？（） A: the signal to noise of the current optical amplifier B: the signal to noise of the previous amplifier or source C: the signal to noise introduced by the optical multiplexer D: the accumulated noise to signal ratio of the optical channel
- 500mW对应的dBm值是()。 A: 27dBm B: 23dBm C: 30dBm D: 20dBm
- 根据dB及dBm的定义，当负载阻抗为____时，dB=dBm。
- 100mW等于（）dBm A: 40 B: 33 C: 20 D: 30
- 以下哪项有关功率的陈述是√的是（ ）。 A: 0 dBm = 1 mw B: 0 dBm = 0 mw C: 以上都不是 D: 1 dBm = 1 mw