有不同类型的过滤器喜欢高通滤波器，低通滤波器，带通滤波器和BandStop过滤器。高通滤波器仅允许频率高于切断频率，低通滤波器允许低于切断频率的频率。带通滤波器将允许特定的频带和带停止滤波器抑制特定的频带。本文讨论了概述了band-stop filter and its working。
What is the Band Stop Filter?
The bandstop filter is formed when alow pass filterand a high pass filter are connected in parallel with each other. The main function of the bandstop filter is eliminating or stopping the particular band of frequencies. The bandstop filter is also referred with some other names like band-reject or notch or band elimination filter. As discussed previously, For high pass filter there will be one cut off frequency, low pass filter also has one cut off frequency but this bandpass and bandstop filters have two cut off frequencies.
这是bandstop过滤器的框图。Low pass filter and high pass filter are connected in parallel. There is some difference between ideal and practical conditions while working with the filter. This difference is due to the switching mechanism of a capacitor. The frequency response can be clearly explained in the above figure.
Band Stop Filter using R, L & C
在电路中电阻器, inductor and capacitor are connected. The output is taken across the inductor and capacitor which are connected in series. The circuit will become a short circuit or open circuit basing on the frequency given at input. For high frequency, capacitor becomeshort circuit电感器将是开路和低频，电感器用作开路等短路和电容器。
由于这种并联连接capacitor and inductor, we can say that at low and high frequencies, it becomes an open circuit and during mid-range frequencies. It behaves as a short circuit. So that’s why mid ranges are not allowed through the circuit and thus acts as a band-reject filter.
The narrow stop band filter is referred to as the NOTCH filter. For the elimination of single frequency, this notch filter is used. It is also called as twin T network due to its two T shaped networks. At center frequency fC = 1/2πRC, maximum elimination takes place.
The capacitor and resistor are used in the notch filter circuit. Capacitor value must be less than or equal to 1µF. the value of the resistor can be calculated by using the equation of center frequency.
This notch filter is very much useful in eliminating single frequency at 50 or 60Hz.
The frequency response of the bandstop filter can be obtained by recording gain and frequency.
Across lower and higher cut off frequencies, bandwidth is obtained. The stopband should have again o0f zero and the passband should have a gain of Amax according to the ideal stop-band filter.
The applications of the band-stop filter include the following.
- The bandstop filter is used in medical field applications like biomedical instruments for the removal of noise.
- In DSL internet services and noise reducers, these bandstop filters are used for removing interference on the line.
Thus, this is all about aBandStop过滤器的完整视图。该频带停止滤波器由一个停止带和两个通带组成。带通滤波器和带停止滤波器特性完全相反。该滤波器也称为带抑制滤波器或陷波滤波器。它在其设计中使用了低通滤波器和高通滤波器。两个过滤器都彼此并联连接。它将有两个切断频率，即低截止频率和高频率。这些中频被拒绝，将允许所有其他频率。这是带停止滤波器的完整描述
Here is a question for you, what is a high pass RC filter?