Re: NEC-LIST: Near field

At 7:38 AM -0400 2000/6/16, Pascale Lutz wrote:
>I'm modelling radiation patterns of a dipole using the near field
>option of NEC-2 (NE and NH cards). The dipole is 1m long and is
>situated either in free space or above a ground (Epsr=3.5 and
>sigma=5mS/m). The frequencies are 150 MHz or 100 MHz.
>
>I wonder if there is a maximal distance from the dipole beyond which
>the calculated fields are inacurate....
>
>I would like to know what maximal distance from the dipole we can
>admit when modelling patterns using the NE card.

I believe that the fields calculated by NEC-2 are accurate out to a
distance of slightly less than 10 km, at which point numerical
imprecision kills you. At any distance the field that NEC-2
calculates in response to an NE or NH command is the total field,
without regard for any distinction between "near" and "far" fields.

-Chuck.
Received on Wed Jun 21 2000 - 14:29:18 EDT