Coplanar Stripline Filter

[RFbeginner]

hello everyone,
i'm designing (or at least trying to ) a coplanar stripline filter, any filter really but online there isn't a lot of informations about that , all the papers i read do not mention how and the formulas used to design the filters, I wrote a matlab code to determine the slot and strip width (using the formula from every book)  and i got 0.769mm for the strip width W and and 0.119mm for Slot width S, which is perfectly confrom to 50Ohm per strip (coupled 100) when i simulated that on CST, I tried various filters i saw online and played with the variables
but the best I got was some losses but nothing that makes a filter, does anyone here have an idea or formulas i could use to design a filter of any kind (BP,LP,HP,BS) knowing that I want it to work between 2 and 3 GHz ?

I would be really grateful.
thanks.

[Benta]

This might help. Check out chapters 3 and 7:

https://userweb.jlab.org/~brads/Manuals/Hardware/ECL_Design_Handbook.pdf

[schratterulrich]

I have realized my first microstrip filters with ANSOFT Designer SV. It's a limited but free student version of a RF CAD software.
Fortunately it includes a very powerful filter design wizard also in the SV version.
You can find the software at http://www.gunthard-kraus.de/Ansoft%20Designer%20SV/
Direct download link http://www.gunthard-kraus.de/Ansoft%20Designer%20SV/English%20Tutorial%20Version/DesignerSV050610.exe

Since it's been some time since i used this software, i don't know if it's compatible to windows 10.

[RFbeginner]

@schratterulrich: thank you ! i'll download it and check it today but it seems that it only does microstrip lines , i'm doing a coplanar stripline CPS ( no ground plane, no vias...) i'll check it more later but thanks a lot.
@Benta thank you but those formulas are for microstrips, i'm designing a CPS coplanar stripline and since its not very used there isn't really any informations about it...

[schratterulrich]

Yes you are right, Ansoft Designer won't support CPS structures.



To be honest, I didn't even know that these filter type exists.

[tggzzz]

Why must it be a stripline filter? What's the unique benefit?