Metamaterial microstrip antenna in HFSS

Hi,

I am trying to produce metamaterial microstrip antenna result from the attached paper by following all the dimension provided by the paper , but when i am trying to plot the S parameter graph it seem like the resonance frequency is at 21.66 GHz when i am suppose to get the resonance frequency around 7.1 GHz... Can anyone help me up in the set up and any possible reason that this is happening..

Thanks and have a nice day!

can someone out there please help me up :) ? i just need some guidance , this is really important to me...thanks !