noise-figure indicator

例句：

1. 1. The noise figure of the device is 20 dB.
   该设备的噪声系数为20分贝。
2. 2.The noise figure of the communication system is very low.
   通信系统的噪声系数非常低。
3. 3.The noise figure of the microphone is measured to ensure its quality.
   麦克风的噪声系数被测量以确保其质量。