frequency lead频率导引frequencyn.频繁；频率frequency of continuous construction流水节拍frequency-modulated carrier system调频载波系统Frequency Coordination Working Group频率协调工作组frequency conversionspeed regulating变频调速frequency modulation for motor speed变频调速frequency-hopping signal generator跳频信号源frequency modulated signal generator调频信号发生器Frequency-modulated radar receiver调频雷达接收机frequency-modulation VF telegraphy调频制音频电报frequency simulation characteristics频率特性