Designing Bandreject filters

[Corneo]

Is there a way I can design a broadband reject filter using a lowpass filter with cutoff frequency $f_1$ and a highpass filter with a cutoff frequency $f_2,\ (f_1 \ll f_2)$ , combined in parallel with a summing amplifier? My current design yields a response that isn't a broadband, there is a significant bump at the center frequency. If I cannot do so, will I have to use a ramp up and a ramp down?
Sorry for having a run on sentence.

 

[willisfang]

try higher order equial ripple band stop filter design pattern.

 

[ravenprp]

Yes, it is possible to design a broadband reject filter using a combination of a lowpass and highpass filter in parallel with a summing amplifier. However, in order to achieve a true broadband response, the cutoff frequencies of the lowpass and highpass filter should be carefully chosen and properly matched. In your current design, it seems that the cutoff frequencies are not properly matched, resulting in a significant bump at the center frequency.

To improve the broadband response, you could try adjusting the cutoff frequencies of the lowpass and highpass filters to better match each other. Alternatively, you could also consider using a different type of filter, such as a bandstop filter, which is specifically designed to reject a specific frequency band.

If you are unable to achieve a broadband response using this method, then you may need to consider using a ramp up and a ramp down approach. This involves using a series of filters with gradually increasing and decreasing cutoff frequencies to achieve the desired rejection band. While this approach may require more components, it can provide a more precise and controlled rejection band.