On the Textron C band and S band antenna range[s] that I managed we had
a practical, that is PRACTICAL, limit of 1000 wavelengths to establish
the far field pattern. I don't know if it is/was technically justified
but it was contractually defined.

Deacon Dave, W1MCE

W5DXP wrote:

Dr. Slick wrote:

I was going to ask you to define "far-field", and i thought maybe
people defined this as a number of wave-legnths away, but if it's
nebulous like a lot of RF topics, then i would certainly understand.


One could define far-field as the point where the E-field/H-field ratio
is and outward continues to be 377 ohm resistive.

The IEEE Dictionary defines "far-field region - The region of the field
of an antenna where the angular field distribution is essentially
independent of the distance from the antenna."