请教书上的问题
时间：10-02
整理：3721RD
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大虾们好，菜鸟问一个弱弱的问题，就是analog design essentially书上的179页，图如附件所示：
At higher frequencies, the output current is divided by two, since the current mirror does not receive any more current. A division by two can only be represented by a pole-zero doublet, the zero of which is a factor of two higher than the pole.
这句话理解不了啊，它是如何得出零点频率在2倍的极点频率处的啊?请大虾们帮忙解释一下啊
At higher frequencies, the output current is divided by two, since the current mirror does not receive any more current. A division by two can only be represented by a pole-zero doublet, the zero of which is a factor of two higher than the pole.
这句话理解不了啊，它是如何得出零点频率在2倍的极点频率处的啊?请大虾们帮忙解释一下啊
razavi书上第157面有推导。我的直观是“当频率比fnd大时，电流都从Cn2
电容流到地，所以这时二极管负载几乎没有小信号电流流过，电流镜就失去作用，输出就一个电流接地，于是这时的放大倍数就为原来的二分之一。所以零点对在低频时为1.在高频时就为2分之1
你的直观理解，我还是不太清楚，为什么“输出就一个电流接地，于是这时的放大倍数就为原来的二分之一”，还请您给我再解释一下可以么?谢谢