dual mode filter design

[zam_nmn]

Hello,

I am newbie in HFSS and would like to ask about dual mode filter design.
I am designing dual mode SSS filter at frequency 1.8GHz using RT3010 with dielectric substrate 10.2 and height 1.27mm. the radius of the patch resonator was obtained from equation a= (1.8412c)/2pi f (dielectric constant)^1/2 .I did my simulation but seems like something is wrong somewhere here is my question :

1)how exactly to calculate the length and width of the feed line?
2)how to calculate the dimension of slot/notch and position slot/notch in HFSS? I have read in few books mention about the slot/notch must be located symmetrically 135degree from output and input port in order to create dual mode, but don't see any equations to calculate the dimension of the perturbation.



https://obrazki.elektroda.pl/2868615200_1421675313.jpg
https://obrazki.elektroda.pl/9257997200_1421675314.jpg
https://obrazki.elektroda.pl/6188797900_1421675315.jpg

 

[tony_lth]

It seems that you have some concepts, just make your HFSS design with variables and then opt them to get your targets.