Re: NEC-LIST: Ansoft HFSS vs NEC etc.

How did you model the supporting structure for the antenna?
I've been looking at just this sort of thing recently (as well as some
interesting papers on interferometry and VLBI dealing with determining
carrier phase without a wire connecting the two receivers.. one with a
fairly youthful picture of you at the end)

> I don't know about HFSS, but NEC-2 or (better) NEC-4 can do what you
> want quite well. I used NEC-2 to design a GPS dual-band (three L1
> and four L2 elements interleaved, with L1 and L2 phase-centers
> coincident) phased-array antenna for precise relative positioning via
> carrier-phase measurements.
> Counselman III, Charles C., Multipath-Rejecting GPS Antennas, Proc.
> IEEE, Special Issue on GPS, the Global Positioning System, Vol. 87,
> No. 1, pp. 86 - 91, January 1999.
>
This would also be available as a pdf from IEEE xplore, if you've got a
subscription, since it's new enough (IEEE Proceedings back to '88)

> I probably still have this paper as a set of Microsoft Word 98 .doc,
> and .jpg and .gif image files on an archive disk, and could email
> them to you if you wished. I may also some relevant NEC-2 and/or
> NEC-4 input files that you could play with.

I'd be interested in the model files.. I'm looking at dual band elements
(one at 1.2-1.4 GHz, the other at 2.3-2.5, each with 80 MHz BW..). I'm not
so interested in the gory details of the design or optimizing, but, more,
getting some sort of abstract numerical model of the gain and phase relative
to a mechanical fiducial, and with the mutual interactions, for a "typical"
high performance antenna, for use in a bigger model of a system designed to
compensate for the variations.

Jim Lux
Spacecraft Telecommunications Equipment Section
Jet Propulsion Lab
Pasadena CA 91109
(818)354-2075

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