50 ohm feed line calculation?

hello, i am working on a multiband antenna with subpatch, the main part of the anteena is finished but i dont know how to calculate the feed line dimension, and i just try the dimension one by one now, are there any efficient way that i can get the dimension?
i am using ADS to simulate my antenna.
many thanks!

In ADS Schematic, go to Tools > Linecalc
This is a tool that calculates the required line width.

the linecalc only calculate the width of feed line at one operating frequency,doesnt it?
however, my antenna is multiband, which frequency should i input ?will it work?

many thanks~!

The change in the line impedance over frequency is very small.

thats mean i can choose either one to input and get the results?

Yes, exactly.

after i get the width, then i should adjust the length of the feed line until i get a good S11 results?
sorry for so many questions, i am new to antenna design, thanks so much!

Ooops ... you said that you want a 50 ohm line, so that the line is matched to the 50 ohm source -> no impedance transformation -> length does not matter

does the antenna design related to the impedance of feed line?