frequency test频数检验frequencyn.频繁；频率frequency conversion system变频系统Frequency Shift Demodulator频率转换调制器Frequency Coordinating Body频率协调机构Frequency Management Office频率管理办公室frequency modulated carrier调频载波frequency multipler circuit倍频电路, 频率倍增电路Frequency Mass Spectrometer频率质谱仪frequency presetting device频率预置器frequency-shift step pair频移步长对frequency domain scrambling频域置乱