【单选题】【消耗次数:1】
用一个截止频率为w1的低通滤波器和一个截止频率为w2的高通滤波器,构成一个带通滤波器,应当使()。
二者串联,并且w1w2
二者并联,并且w1w2
二者并联,w1w2
二者串联,w1w2
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