在電子學領域，一種不希望發生的低頻電流，它干擾所要求的信號。通常這種現象是由於交流供電線路屏蔽不良引起的。
In electronics, undesirable low frequency currents interfering with a desired signal, and usually caused by a poorly screened alternating mains supply.
以低於信號中最高頻率兩倍的頻率進行信號取樣時出現的一種效應，即當由取樣狀態還原時，還原后的信號將不再含有原來信號中的高頻成分，並將顯示出虛假的低頻信號。
An effect that occurs when a signal is sampled at a rate less than twice the highest frequency present in the signal.The subsequent signal recovered from the samples will not contain the high frequency component of the original signal and will display a false low frequency signal.
