NEC-LIST: Surface currents (was: Modelling Software)

Derek,

You may like to try to develop a model for the surface currents with
Concept, since there is no mention of an archive anywhere a copy of an
older posting is attached below. If there is an archive somewhere, do
let me know....

Talking of enclosure you may be interested to read a recent paper ...
Fast Evaluation of the Shielding Efficiency of Rectangular Shielding
Enclosures by Wallyn, W.; Olyslager, F.; Laermans, E.; De Zutter, D.;
De Smedt, R.; Lietaert, N. 1999 IEEE International Symposium on
Electromagnetic Compatibility Volume: 1 , 1999 , Page(s): 311 -316

I am just a user with no affiliation to the author (TUHH). It provide
a quiver/arrow plot and I consider it a good place to visualise the
surface current density distribution. The examples presented on the
TUHH website do not do justice to the capability of CONCEPT. If you
are still interested, view these file.

The following are my data on a continuous noise emitter (CNE).

Surface Currents: EUT with 10cm dia. top loaded antenna, 0.8m above
Metallic Ground Plane
http://www.geocities.com/timfoo6143/cne_curr_100M_front_ed.pdf

E Field Strength (Radiated Emission) of EUT with 10 cm dia top loaded
antenna. Box placed sideways 0.8m above ground for maximum horizontal
polarization.
http://www.geocities.com/timfoo6143/cne_E3m_1_ed.pdf

Question about cost etc... write to TUHH. I will be happy to answer
questions about its uses and applications.

:-)

Tim Foo

---------------------Copy of Old Posting-------------------
(Slightly Off Topic)

I suppose you are looking for a frequency domain solution with a
Method of Moment (MoM) technique? I have been using CONCEPT (it was
written by TU-Harburg), works on a LINUX platform on a PC. Mind the
instruction manual, you will have to read between the lines (English
words written with a German flavour! :-) ). You will have a whale od
a time reconciling your measurements and simulation results. It can
be highly dependent on your meshing all those quadrilaterals. See the
page on "Microstrip patch antenna on finite dielectric grounded slab".
Mind you get the (1) most SRAM, (2) fastest SCSI HDD and the (3)
fastest CPU money can buy before you begins. Some of my simulations
runs into the weeks.

The CONCEPT, code I suppose can be delivered ready to run, say one set
each for 16, 64, 256 and 1024 MB systems? This is cause by the lack
of a feature to do with dynamic memory allocation, possibily by
isolated portions of legacy fortran codes.

Since this is a NEC forum, I must add NEC 4. If you can get hold of
NEC 4 (subjected to export regulations), it may be able to work on the
half space between the air-dielectric medium. Because it is still
controlled by export regulations I have not use it to verify this.

Hope this helps.

Tim Foo

MoM
http://www.sethcorp.com/technical/mofm.html

CONCEPT II (TU-Harburg, Germany)
http://www.tu-harburg.de/~tegb/descript.html

meshing
Microstrip patch antenna on finite dielectric grounded slab.
http://www.tu-harburg.de/~tegb/micpatch.jpg
Received on Sat Mar 18 2000 - 13:11:36 EST