Designing elliptical patch antenna using superstrate in CST

Hello,
I'm trying to improve the gain of my antenna using superstrate. I read a few journals regarding this topic but i could not determine the thickness of the superstrate needed.
The frequency that i need to obtain is 5.8GHz and i'm using coaxial feed. This was one of the papers i referred. The thickness of my ground plane is 0.035mm, substrate 1.6mm and my patch is 0.035mm. By following the method from the paper, i calculated that the thickness of my superstrate should be about 2.105mm. The superstrate that i'm using has an epsilon of 10.2 and my substrate is 4.9. Please correct me if i'm wrong. Any help would be greatly appreciated. Thanks..
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using CST,you can use parametric sweep to find the best thickness of the superstrate I think it's not any deterministic relation for thickness of superstrate so the general solution is trial and error.

Thank you project.email for your reply. I would like to ask does superstrate actually enhances mutual coupling as i manage to increase the gain and radiation efficiency but the VSWR is about 1.6 with return loss of -11dB. Does it make a good antenna ?

11dB return loss sounds more like 1.78 VSWR. generally speaking vswr of 2and below is good for the bandwidth of frequencies.
Cheers

General speaking ,using the superstrate layer because of increasing the size of antenna , it cause to reduce the resonate frequency.
in some case by using this layered we can tune our antenna to resonate at a desired frequency.

Hi..I did also used parasitic ring element to increase the gain which in the journal does not actually specify the thickness of the copper used as a parasitic element. Does it also based on trial and error ? I managed to really improve the return loss as it was about -48.9dB with VSWR of about 1.005.
But the gain was still low. This was the journal i referred :-
http://www.ijetch.org/papers/219-T644.pdf

It was same problem for me when i wanted to design the PIFA antenna in a lossy medium there wasn't any deterministic relation to do it,so i must use trial and error.
in fact i don't know for your design is there any deterministic equation or not.The writer of the mentioned paper had referenced to Balanis antenna,look for it in that book,it may be useful for you.try it.
and the last suggestion of my experience is that ,usually in the paper the writer don't show the whole dimensions that you need to get the correct result.you by yourself should find it.
also you can email to the writer of the paper and ask him/her to know the thickness of the parasitic element.
best wishes.

Thank you project.email for your help. I will look into it.