Re: NEC-LIST: Parallel wire modeling question

The problem here is not just the thin-wire approximation, but the
fact that any variation of the current around the wire is ignored -
common to most wire programs. Thus you would need to account for
such a variation. You might do that with an equivalent distance
adjustment based on electrostatic approximations to the quasi-TEM
fields in the vicinity of the wires if they are very close. Such a
solution can be found in almost every UG textbook on fields for
parallel wire stuctures. Bill

Date sent: Wed, 18 Jun 2003 11:11:08 -0400 (EDT)
From: "Kapil R. Dandekar" <dandekar_at_cbis.ece.drexel.edu>
Subject: NEC-LIST: Parallel wire modeling question
To: nec-list_at_gweep.ca
Copies to: "Kapil R. Dandekar" <dandekar_at_cbis.ece.drexel.edu>

> Hello there,
>
> I am using NEC2 to model a wire antenna approximation of a half-wavelength
> dipole antenna array operating around 2 Ghz. I am looking for references on
> how close parallel wires can be before underlying assumptions regarding the
> thin wire approximation and lack of circumferential currents are no longer
> valid. Specifically, people seem to use parallel wires with 0.5*lambda
> separation relatively frequently. How much closer can they be before
> assumptions start to break down?
>
> The NEC2 documentation states "at leaset several wire radii" separation,
> but this is somewhat vague. I know that people use fine wire meshes for
> approximating surfaces, so I am confused as to why an inter-element spacing
> of, say, 0.1*lambda would be a problem.
>
> I have been told that it depends upon the length of the parallel wires
> being modeled, but I couldn't find any references. Any references or
> suggestions would be appreciated.
>
> Thanks,
> Kapil
>
> ___
> Dr. Kapil R. Dandekar
> Assistant Professor
> ECE Department - Drexel University
> 3141 Chestnut Street, Room 7-515
> Philadelphia, PA 19104-2875
> Email: dandekar@ece.drexel.edu Web: http://www.ece.drexel.edu/wireless
> Phone: (215)895-2004 Fax: (215)895-1695
> --
> The NEC-List mailing list <nec-list_at_gweep.ca>
> http://www.gweep.ca/mailman/listinfo.cgi/nec-list

-- 
The NEC-List mailing list <nec-list_at_gweep.ca>
http://www.gweep.ca/mailman/listinfo.cgi/nec-list