The best software EDA for design of antennas?

Advanced Design Systems (ADS) momentum analysis

there are alot , IE3D , and HFSS

khouly

CST ,IE3D,ADS or HFSS

Not forget Mmana from http://mmhamsoft.amateur-radio.ca/ !

u can try mmician wizard also

which of them is closer to measurement? how much error? especially in gain.

?CST, IE3D, ADS or HFSS?, could, please, place links?

CST: http://www.cst.com/
IE3D: http://www.zeland.com/ie3d.html
ADS: http://eesof.tm.agilent.com/products/ads_main.html
HFSS: http://www.ansoft.com/products/hf/hfss/

ultimately ansoft hfss 9.0 ..the best..

Added after 54 seconds:

u can try Flomerics' Microstripes 7.0 if ur design is of not more complex type and needs little meshing.