Help In HFSS patch antenna reports

Hi everyone.
I am new to Hfss,when i used to design the patch antenna of the manual of hfss,it gives correct results,but when i design my own patch antenna or any patch antenna of any research paper ,it does not give correct results,it resonates at multiple frequency and its S11 graph is also not smooth.now i don't know what and where is wrong ?any one who knows about this?
Secondly I am Analyzing every time whenever i change one of the parameter.which take too much time.is there any technique so that i can integrate all responses of changing one parameter in single report window so that i can see the difference which is usually provide in research papers.
thank you in advance.