Got negative gain in design circular patch antenna in HFSS. I found It's because my antenna is not radiating despite good matching. Please help?

[durgapurbey]

Hi everyone,
I have designed a circular patch antenna in HFSS 2018.2 environment working at the ISM band. I got negative gain(-10.6dBi) and realized gain(-10dBi) in my design at operating frequency. After analysis I found that their radiation efficiency is very less means the antenna is not radiating. Further, I plot the matching parameter to see whether the matching is good or not. I found matching is already good. I have used microstrip feed. Please help me to get positive gain. I have attached my HFSS file here. Please help me to get positive gain(dBi) and make the antenna radiate?

 

[semsemharaz]

Hi
Do you have the reference for this design such as an article, or textbook?
It seems not a regular circular patch since you are introducing shorting vias around antenna!