Need a help regarding impedance mismatch problem in HFSS..!

I've designed an antenna for operating frequency 31 GHz but i'm unable to get gain on this operating frequency its coming in negative value, instead i'm getting high gain at 28 GHz.

someone please give me a solution to achieve gain desired operating frequency what should i alter for achieving it?

I think you have a idfusehfwf antenna, so the solution is uifzuzuwfezwe.

what do you mean by idfusehfwf antenna and uifzuzuwfezwe. i cant understand.

Neither we can't understand your problem because you didn't give any useful information about your antenna design.

But you could try to reduce all antenna dimensions by 10 percent....

Cool down FvM cool down...

i have attached an image file of my antenna design i've designed it using HFSS. its a hybrid structure of a slot coupled circular patch antenna with a surface mounted conical horn designed for 31GHz frequency with gain 12 db.A
microstrip circular patch is printed on a low permittivity 2.33 grounded substrate that is 0.7874 mm thick. The
patch is fed by a 50 ohm microstrip line on the backside of a
second 0.635-mm-thick dielectric layer with a higher permittivity of 10.22 through a rectangular coupling slot etched
in the ground plane.

dimensions are
W=15,L=20,Ws=.25,Ds=13,h1=.635,h2=.7874,Wf=.65,Lf= 10.64,hc=7.875,rc=6.5,rp=1.48,Ls=2.3 all dimensions are in mm.

if you could further help me regarding it i'm pleased for your reply..!
if any other information regarding the design is needed please let me know.