Resonator structure for 900 MHz

Hi
I design a patch antenna for UHF 900 Mhz

dimension patch :
W= 10.21 cm
L =80 cm

dimension ground
W=11.17 cm
L=80.96 cm

Substract Er = 4.32
h = 0.16 cm

air box
Xsize= Ysize=Zsize = 120,96 cm


using coaxial feed i try many position but i can't find a good result close to 900MHz

1) how can i find a good position ?

2) i want to use a resonator for i read many thing about them " SRR split ring resonator " but i cant find a good structure for 900 Mhz because i want to compare two structures structure with resonator and structure without resonator

What's the intended resonator mode and radiation pattern? How did you arrive at 80 cm length?

Ignoring the question how did you arrive to these dimensions, can you take a picture please of the (almost) 1m patch antenna, to see how it looks?

sorry its a mistake :( the good results is L=9.41 cm
and Lg= 10,37 cm

air box
Xsize= Ysize=Zsize = 30 cm

i need a resonator SRR because it's for a negative permetivity ( because in HFSS i can't work with negative permetivity)

metamaterial have a negative pemetivity