The component having the lowest frequency in a complex vibration (fundamental frequency or first harmonic).

复杂振动中频率最低的成分(基频或一次谐波)。

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Also, the harmonic filter is a low pass filter having a frequency cut-off point that attenuates first order harmonics of the output signal.

此外，谐波滤波器是具有频率截止点的低通滤波器，该低通滤波器削弱输出信号的一次谐波。

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