how to find the frequency range of log-periodic wideband antenna in emc measurement since there are alot of wideband frequencies? and for the design shud i use 3d?i mean shud i use hfss software?
generally EMC logperiodic antenna has a bandwith starting from 200MHz up to 2000 MHz (or, in some cases 4000 MHz).
You can find more information on website's vendor like Schwarzbeck.
Regarding the design I personally use a full wave MoM (Method of Momenth) simulator.