Hello,
I have a question about Far-field
conditions.
I know two formulas for the Far-field
calculation :
Lambda/2pi and 2D²/Lambda.
My question is about a Broadband Horn like 2-18
GHz.
I don't know if I have to use the 2D²/Lambda
even for the low frequency ?
I heard if the
antenna was electrically small I had to use the
first formula but what is the electrically small
definition ? (Aperture size < to Lambda or more
?)
Thanks for your help.
Guillaume