AC frequency system  交流调速系统

Active radio frequency system  高速公路网

Atmospheric Low-frequency system  低频天气系统

beat-frequency system  拍频系统

bi-frequency system  双频制

calibration of system deviation  系统偏差校正

Correcting Deviation System  纠偏系统

Deviation System  偏转系统

Digital Network Audio Frequency System  数字网络音频系统

digital video frequency system  数字视频系统

Low frequency system  大气低频系统

Microwave radio frequency system  微波射频系统

multi frequency system  多频制

Power System Frequency  系统频率; 电网频率; 电力系统频率

Power System Frequency Measurement  电网频率测量

radio frequency system  射频系统

shipboard integrative radio-frequency system  舰载综合射频系统

Standard time and frequency system  时频基准系统

stepped-frequency system  步进频率系统