frequency lock锁频frequencyn.频繁；频率frequency distortion transmission impairment频率失真传输减损frequency modulation/amplitude modulation调频／调幅frequency-conversing and speed-governing变频调速frequency-domain lowpass filtering methods频率域低通滤波法frequency crucible induction melting furnace频率坩埚感应熔炼炉frequency odulation telecommunication system调频通信制frequency monitoring and interference control频率监测和干扰控制frequency-programmed microwave spectrometer频率程序控制微波光谱仪frequency domain convolutive blind separation频域卷积混合盲分离frequency modulated carrier current telephone调频式载波电话