problems with a dual band antenna simulated in IE3D.

ie3d literature

Hi all,
I am trying to learn IE3D, to simulate a pifa antenna, and for training I am simulating pifas found in articles and compare my results to what found the autors.

unfortunately for every pifa I simulate my results are wrong I don't know why.
In the beginning I had a doubt about the basIc parameters which were not defined in the articles, so I tried to get one where they are defined and also my results are wrong.

Can any one chek my work here attached and tell me what are my errors.

THAKS IN ADVANCE, EXCUSE THE DISTURBING I CAUSE.

BEST REGARDS.

Hi, Alberich:

I am not quite sure why you think your results are wrong. I checked it. As it is, it is already not bad. I can see there are some differences in the resonant frequencies and the depths of the resonances. However, those differences are mainly due to the fact that you did not use automatic edge cells (AEC). AEC is always suggested when you want to get high accuracy results. If you turn on AEC, the results will match the results from the literature much better.

I checked some dimensions of your built and it seems to me all the checked dimensions are matching those on paper. I can still see some differences in the depths of resonances. However, it is not so critical because some minor changes in dimensions may cause the difference anyway. I will check the dimensions for you.

Regards.

HI DR JIAN,
thank you for helping me,
but what about the errors messages I get :

the first one is about the twisted poligons, it tell me that they will be removed does it influence on the results?

about the AEC when I chek it, it was with 0.002 size, so I get a message error telling that is less han 1% so I put it into a size giving 1.1 % does it correct?

thanks in advance and excuse the disturb.

receive ALL MY RESPECTS,
BEST REGARDS.

Hi, Alberich:

1. The message of twisted polygons is not critical normally. Most of these messages are due to over sensitive deteciton. It is for a case like the following:

a-----b a----b a----b
| | | \ | | / |
d-----c d----c d---c

abcd is a 4-vertex polygon in 3D. If the 4 vertices are not on a plane, we have to divide it in either one of the ways shown above. They do not represent the same structure when they are divided when abcd are not on a plane. If they are on the same plane, they will represent the same structure no matter how we divide it.

Due to some sensitivity in the detection, it may detect abcd are slightly off a plane and it will issue you are message. Normally, it is not critical.

2. You should normally use aec ratio = 0.1 or 10%. You may adjust it to smaller value for narrow strip structure. For your structure, using 1.1% is too small.

Regards.