Two sharp attenuation poles can be located close to either side of the desired pass-band to improve the frequency selectivity.
两个衰减极点分别产生在靠近通带的两边，提高了通带频率的选择性。
2
In the paper, the calculating method of signal extraction filter pass-band according to the paper-counting speed and the utility circuit of separating strong interference in pass-band are given.
并针对点钞速度给出了信号提取滤波器通频带的计算方法，以及在带内分离强干扰的实用电路。
3
The first to pass is Tootles, not the least brave but the most unfortunate of all that gallant band.