frequency zone频率带frequencyn.频繁；频率frequency modulation tuner调频调谐器frequency response plotter频率响应绘图仪frequency character viewer频率特性观测仪frequency sampling theorem频率抽样定理frequency doubling circuit倍频电路frequency difect repeating频率直接转发法frequency selective switch频率选择开关frequency spectrum monitor频谱监测frequency of family stress家庭紧张频度frequency response masking频率响应屏蔽