A couple of months ago I posted a question on how to design an elliptic filter made out of micro stripline. That got me some pointers but not a clear answer. After some more Googling I found a book which had a couple of equations. Those are so difficult to solve I couldn't get away with an Excel sheet let alone solve them by hand. So decided to write my own solver. Being at it I wrapped it into a nice GUI and I decided to turn it into a (cheap) product.
Ofcourse I did some simulation and testing and it turns out the geometries calculated by my program produce working filters!
It available for download from my website:
At this moment it can only calculate geometries of 3rd, 5th and 7th order elliptic filters (which is by far the hardest part).