Help regarding AMC structure analysis in CST

Hi!I am TJ....I am working on a project concerning "RFID antenna design using Artificial Magnetic Conductors ".
I have been using the paper......"Low-Profile RFID Tag Antenna Using Compact
AMC Substrate for Metallic Objects" paper as a reference .I am using the AMC structure given in the paper to get 0 phase at 915 Mhz........i am using 5 by 2 structure as given in paper.....however I am not sure how to begin with the analysis in CST............I have read most of the posts here..............and I have observed waveguide method,plane wave and periodic conditions + macro to be a contender.........I have simulated using waveguide method(using 2 PMC and PEC)...........but the results do not tally with the paper...............also I have seen the results vary Z the height of waveguide...............could anyone give answer to following questions.......

1)What value of z should i keep for anlaysis?
2)Which method should i used for analysis out of the 3 methods?
3)can i put whole structure inside waveguide instead of doing by unit cell?if yes then what boundary condition should i keeep in that case.....

Any help would be appreciated!!!



p.s-file attached for reference