Notch filter (Notch Filter):
The notch filter is a band stop filter, the stop-band is very narrow, and therefore also known as point-stop filter. Often fixed for removing a frequency component or narrow stopband place. As for removing a DC component removing specific frequency components.
Peak filter with a notch filter on the contrary, the peak filter is a band-pass filter, which is a very narrow channel. Often narrow place for reserving a fixed frequency components or channels.
Notch filter design:
Here, a design application to DC.
designing process:
By filterDesigne design, "Response Type" select "Notching", in the "Filter Order" input 1, then fill "Fs" and "Bandwidth" Apass and the like. Finally, it will be a first-order IIR filter.
Num = [0.9983, -0.9983]; when = [1, -0.9967];
![](https://img-blog.csdnimg.cn/20190517131535329.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2tlbWk0NTA=,size_16,color_FFFFFF,t_70)
When FPGA implementation, some indicators can be adjusted to optimize the coefficient, it does not use multiplier DSP.
![](https://img-blog.csdnimg.cn/20190517133435204.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2tlbWk0NTA=,size_16,color_FFFFFF,t_70)
Thus, when the FPGA implementation, only need to be taken to cut off the way.
or,
When implemented, the shift multiply add replacement, division replaced with truncation.