T.l matching

hi all, i have a problem with my design i've got adesign ct that operates at 1G -and it has aT.L matching to the feedback loop which is a rod of copper with mentioned dimensions- i have changed the values of the ct and i tested it on ADS tool and it worked .... but i still have aproblem with the matching rod how can i know its equivalent values ( model) tp change the dimension to the new frequency..
regards,