Far-Field formula for Broadband Horn - RF Cafe Forums

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gui076
 Post subject: Far-Field formula for Broadband Horn
Posted: Wed Jan 26, 2011 6:35 am 
 
Captain

Joined: Mon May 05, 2008 9:56 am
Posts: 15
Location: France
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




Posted  11/12/2012