Patch antenna co polar and cross polar components

hi

i am tyring to understand the copolar and cross polar field components of patch antenna

i have simulated a simple linear polarized microstrip fed patch antenna in CST

it is lying in xy plane. with the patch length along x axis and width along y axis

now when plot the far field pattern cut in xz plane which is the E plane . Etheta is the dominant component(co polar) while Ephi is the minr component ( cross polar)

however when i plot yz pattern cut which is the H plane of antenna , Ephi is the dominant (co polar) component while Etheta becomes the minor ( cross polar) component.

i am unable to explain this phenomenon

all people are welcome to comment on this topic .

just give any views

regards