無源雙T陷波器電路(Twin-T passive Notch Filter)

圖1是雙- T的無源陷波器陷波濾波器電路，陷波器是某一小頻率范圍內的帶阻濾波器。陷波器的一個常見的應用是濾除60赫茲左右的交流電噪聲。這一雙 T的陷波器最常用的一個陷波濾波器，兩個T型網絡組成。T網絡由一個電阻和兩個電容組成，其他有兩個電阻和一個電容器則組成另一T型濾波器.如圖1所示的陷波頻率約在Fn = 1 /（2πRC）。

圖1 無波陷波器電路圖

A notch filter is a circuit that rejects a very narrow band of frequency. A common application of a notch filter is the removal of the 60-Hz hum from an AC line. The twin-T filter, one of the most commonly used notch filters, is a passive filter composed of two T-networks. One of these T networks has one resistor and two capacitors, while the other has two resistors and one capacitor. For the twin-T notch filter in Figure 1, maximum attenuation occurs at fn = 1/(2πRC).