HFSS convergence warnings

[xx_kitaro]

hello
I am doing simulation on corrugated horn antenna in 15 GHz using HFSS . after completing the simulation it gives following warning
[warning] Adaptive Passes did not converge based on specified criteria.
[info] Normal completion of simulation on server: Local Machine.

How can i remove this warning message and what do these warnings mean and how do they affect my results?
thanks

 

[BradtheRad]

Some convergence problems can be solved by changing the timestep. Try 20 to 100 times as fast as your operating frequency.
Example, 1 pico-Sec may be suitable.

Many simulators require that your schematic have at least one ground connection.

Additionally, simplify your schematic so that you have easy components for the simulator to calculate. Omit nonessential IC's.

When you get a bare schematic working, than add the other components.

 

[xx_kitaro]

I am doing frequency domain simulation, actually I increased the steps and adaptive passes but no difference occurred at the end of the simulation, for more simple antenna structure the simulation converge to answer with out any warning but when I add corrugated parts it doesn't converge
anyway thank you for your reply