combline filter layout
HI,
You can simulate the combline filter or cavity filter in 3D simulator like HFSS.
1 create the filter in the HFSS
2 add lump port on top of each resonaor
3 add tap line and wave port
4 simluate it and then export the S-parameter into linear simulator like ads or designer 2.2
5 attach port to the wave port , attach capacitors to the lump port
6 the capacitor can tune the freq of the resonaor
finally add 1/4 wavelength transsimison line to adjust the coupling for better return loss
Hope it helps
James