any help for s-parameter of Coaxial patch antenna + CST

Hi everybody!
i designed a patch antenna with coaxial feed by CST, but after simulation, i get a strange results for s-parameter, and gain is about -200 dB and more.
can somebody tell me what is wrong with my CST design.
f =1.9 GHz , L =22 mm, W=31 mm, dielectric constant 11.9 , h=1.5 mm.

S11 is obviously 0 dB. There might occur some computational error caused by computer (Not yours, in general). If you attach the gain plot, someone can comment on result.

check ports, mesh, plot fields to see if there's something setup wrong.

can anyone explain how to set mesh ?