coupling patch antenna in E plane

hello

in the study of E-plane coupling between two patch antennas (to draw the S parameters s12 for example)
what is the most correct dispositionnement (case 1, or case 2)?
and what is the difference between case 1 and case 2

thank u very much

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I do not think that these two cases have the same meaning

in balanis , he worked with the second case (case 2)