# calculation of field in the near field region of an antenna

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#### cross

##### Member level 4
near field calculation

Hi,
Anybody nows the easiest way (or software) where you can import an antenna pattern or structure and check how much is the received field in the near field region or how this field diminishes in the near-field region with an increasing distance from the antenna? The interest here is for large antennas and small frequencies where the far field could be several 10ths or 100s of meters.

Any input would be greatly appreciated

Kind Regards
Cross

#### Matt

##### Junior Member level 3
calculation of field strength near field

For simple structures such as monopoles, dipoles you can simulate with NEC. You can define a near-field monitor and plot field strength against distance. I have used similar for 5m antenna at 2MHz successfully.

#### sai_krishna9588

##### Newbie level 5
Re: calculation of field in the near field region of an ante

try visiting the antenna supplier wb-site like Alan& Dick Company

#### limate

##### Junior Member level 2
Re: calculation of field in the near field region of an ante

HFSS may also fit for this job.

#### mogwai

##### Full Member level 3
Re: calculation of field in the near field region of an ante

A great commercial software for this purpose is NFA3D (Near-Field Analyzer), by Aldena (italian company - specializes in antenna system and simulation software)...

check out this site for screenshots and demo:

/www.nfa.it

hope this helps
mogwai.

#### jian

Re: calculation of field in the near field region of an ante

IE3D 10.x has near field calculation and visualization from either robust calculation from Green's functions (slow but precise) or pattern calculation (fast but approximated).

#### cross

##### Member level 4
Re: calculation of field in the near field region of an ante

Thank you all for the info. Do you know if you can define a parabolic antenna in IE3D?

Kind Regards
Cross

#### eirp

Re: calculation of field in the near field region of an ante

Hi

Yes, you can construct parabole in IE3D but as far as I know it's little tricky.
You probably will have to create .3dt file and construct it from number of polygons. Maybe script in Matlab would be necessary
I'm also afraid about memory requirements, problem is supposed to be very electrically large
In MWS of HFSS creating a parabole is question of 2 minutes

rgz

eirp

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