frequency lead频率导引frequencyn.频繁；频率frequency modulation phase modulation调频调相Frequency-Modulated Continuous Wave调频等幅波frequency multiplication phase-lock倍频锁相Frequency-selective fading channels频率选择性衰落信道frequency synthesizer including mixer含混频器的频率合成器frequency divison multiplex telephony频分多路电话Frequency Division Multiple Access LT频分多址frequency modulated television system调频电视系统frequency-controlled water-supply变频供水frequency-modulation broadcast band调频广播波段