Band pass filter design in HFSS

[Ram_sek]

Hi friends,

I have designed 3 rd order band pass filter in HFSS. For short circuit stubs, i used a small cylinderical hole in HFSS with radius as 0.4mm. Is there any standard formula or dimension ?

Please guide me

 

[megaknaller]

By "hole" do you mean a via between your signal trace and ground? If yes, the main requirements are that the hole/pad diameter is less than lambda/4 of your design frequency. This hole condition is required for it to not radiate (losses) and the length of the via should be less than lambda/4 in order to avoid an impedance transformation at the short circuit point or radiation losses.

Hope this helps