Adding notch/reject filters in series

[jujun]

Hello,

When adding notch/reject filter by putting them in series, will it work?
Is it as easy as the losses are added and nothing more complicated? It sound a little too easy...

And what about the length of cable between the filters ?

Basicaly, I want to block two annoying signals, that are one each side of my band of interest. Is it good to make a notch/reject filter for each ?
Because if I make a band pass, on UHF, the loss are too big. But the added losses of two reject filters are not a very big. 0.5db + 0.5db it's quite good

By the way, why it's so different ?

Thank you for any advices

Julien

[ejeffrey]

As long as the notches don't overlap it should work fine.  If they overlap there will be a standing wave between the filters and rejection may decrease at some frequencies relative to a single filter.

[jujun]

As long as the notches don't overlap it should work fine.  If they overlap there will be a standing wave between the filters and rejection may decrease at some frequencies relative to a single filter.

Thank you!
So it's wonderful, and it's a lot better than making a band pass!

I will try to make very broad band block filter to see if it's possible to have low losses.

[CopperCone]

You can put an isolator between reject filters of the same notch i think

[jujun]

You can put an isolator between reject filters of the same notch i think

What is it ?

[Wolfgang]

Tip: You could simulate the circuityou have in mind  using SPICE you have in mind so you can predict the effects.

I notoriously do this, results are OK:

https://electronicprojectsforfun.wordpress.com/rf-module-gallery/the-rf-filter-gallery/