length claculation same

hi to all,

any one tell me that the length calculations for the both interdigital and combline round rod cavity filters are same or not?(becas it only depends on frequency )

thank you

I think, resonator length is decided by wavelength, frequency,and Er

yes i know the formule and all, but my doubt is whether the the length of the interdigital and comb line is same or not ? thats it!