Re: NEC-LIST:Gain for helical antennas

Good day Claudio,

You should only sweep theta from 0 to pi/2. This covers the half-space
above the ground plane. You should also look at plots of gain vs. theta to
see if your results make sense.

Doug Miron

----- Original Message -----
From: "Claudio Siviero" <sivi.cla_at_libero.it>
To: <nec-list_at_gweep.ca>
Sent: Wednesday, July 24, 2002 1:59 AM
Subject: NEC-LIST:Gain for helical antennas

> Dear friends,
>
>
>
> I'm an italian student of electronic engineering an I doing a dissertation
for
> Antennas examination at the Politecnico di Torino.
>
> The argument is helical antennas used at beam mode and normal mode.
>
> I yields simulations with NEC-2, The antennas are over a perfect ground
plane.
> >From results there's a thing that make me wonder: the gain function
sweep
> theta angle (for the cases azimuth 0 and 90 degrees) of every antennas has
> double angles that I'm waited..
>
> So mean that the HPBW (half power beam width) is double respect those
defined
> by the Kraus's theory in your book "Antennas"; converseley the maximum
gain it
> ok (I hope it!).
>
> A gain function as this hasn't integral sweep theta equal to 4*pi srad but
> higher thant this.
>
> I've thinked that is an effect of the infite and perfect conductor ground
> plane that I used in the model of every antennas, that it changes the
current
> distribution at the interface.
>
> How I shall to interpret these result? What is the cause? How I can to
obtain
> the real gain function? Is there any mistake of evaluation that I'm doing?
>
> If anyone can answer me, I will thank so much!
>
> Bye, Claudio Siviero.
> --
> The NEC-List mailing list <nec-list_at_gweep.ca>
> http://www.gweep.ca/mailman/listinfo.cgi/nec-list
>

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