HFSS : questions about Hertzian-dipole excitation

I've been using HFSS to simulate the radiated power of nano particle ,the excitation is hertzian-dipole (I*Dipole Length=1A*m,Type of dipole is Electric dipole (Magnietic current loop ),Hertzian-Dipole wave options：radius of surrounding Sphere is 10mm which is much bigger than the boundary ),but now ,the results do not agree with theoretical calculation and some papers which use MMP and BEM ,I wanna know whether the setting up for the dipole is correct or not ？Or some advice?
Thanks!

you radius of surrounding sphere needs to be much smaller :) I tend to go for a radius of about lambda/10 depending upon the simulation

Have Fun

Thanks for your reply,I have tried it with the radius about 60nm(about lambda/10) ,20nm,10nm,5nm,but the results show that 10nm is better .
thanks!