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Questions tagged [antenna-modeling]

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Use for questions about using antenna modeling software to simulate an antenna system and determine its gain and radiation pattern.

49 questions
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1 vote
0 answers
122 views

Conversion from nec2 geometry to x3d or some other format to read nec2 geometry files into (ultimately) OpenEMS would I think be good. I found a reference in a document ...
Pete's user avatar
  • 11
4 votes
0 answers
116 views

There are research and examples of "fractal antennas" where the radiator is in a "fractal-like" shape, mostly to save space. Those antennas often come with a penalty in gain (...
Ryuji AB1WX's user avatar
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2 votes
1 answer
85 views

What phase and gain information from the nec output do I use as input for PHASEPAT32. I am dabbling with designing dish feeds and found a great programme by W1GHZ that computes the illumination ...
Phönix 64's user avatar
  • 165
1 vote
1 answer
178 views

I am trying to simulate a helical antenna for 1.7GHz and would like to extract the phase centre so I can correctly mount it at the focal point of my dish. But I do not know where to find this or how ...
Phönix 64's user avatar
  • 165
0 votes
2 answers
157 views

We live on the 4th (top) floor in a suburb of Oslo. The building is concrete, and there are two balconies. I would like to model both balconies and try to optimize some HF antennas for various bands....
ecloud's user avatar
  • 103
3 votes
1 answer
114 views

According to the documentation: "Studies of the computed field on a segment due to its own current have shown that with the thin-wire kernel, Delta/a must be greater than about 8 for errors of ...
KJ7LNW's user avatar
  • 939
1 vote
1 answer
163 views

I'm considering using this 1/4" aluminum tube to build a cross-yagi antenna in the 2m band. The tube dimensions are 1/4" OD x 1/8" ID x 1/16" Wall (.250" x .120" x .065&...
KJ7LNW's user avatar
  • 939
3 votes
1 answer
160 views

Question How would you reason about charge and current density in your design to better tune (and understand) your antenna? Background According to the NEC2 documentation, "The output may ...
KJ7LNW's user avatar
  • 939
1 vote
1 answer
242 views

Why does the power density of yagi antenna beam propagation diagrams increase as the distance to the source increases? Shouldn't the signal get worse as the distance increases or does that only happen ...
mkocrehjuko's user avatar
  • 13
5 votes
2 answers
283 views

I have a number of immovable metal roofs that are near my antennas. I'm wanting to model how these affect my antenna performance. Is there a way I can put a metal plane into my models on 4nec2?
David Findlay's user avatar
  • 171
2 votes
1 answer
565 views

When modelling a Yagi in NEC the radiation pattern is essentially identical whether a conductive boom is included or not, see pictures below. An explanation says this is a limitation of the method of ...
butterflypea's user avatar
  • 33
2 votes
2 answers
350 views

I made a 7 MHz antenna trap. On testing it the cut-off point was 6.687 MHz which is about right but the problem I've got is the SWR was an 8 and wouldn't go down to a resonant SWR. What have I done ...
chris cutting's user avatar
  • 21
1 vote
0 answers
103 views

I've looked at the various guides I found on the 'web, and I cannot find a single example of a 4nec2 deck that has a variable or formula in one of the integer fields. But at the same time, none of ...
Maury Markowitz's user avatar
  • 175
1 vote
2 answers
115 views

I'm trying to understand the use of GS cards in NEC2 decks. The documentation is rather vague! Consider a basic stack: ...
Maury Markowitz's user avatar
  • 175
2 votes
1 answer
110 views

I've been seeing this #nnn pattern in SY cards a few times, but I can't find any mention of it in the documentation. I'm ...
mcmayer's user avatar
  • 123

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