hfss 4-element antenna array!

im doing this project on phased array antenna, i hav designed an array of 4-elemnts using the corporate feed method, but the problem is with the rectangular plot i.e im not getting the correct resonant freq dip..

im attching the hfss files for the single patch and the array, plz look at it and tell me what mistake im making..thnx[/b]