Re: Helical Antennas

I would like to hear more comments on this subject. I cannot see why
the NEC-like modeling does not apply to helical antennas at least in
the normal mode (small antennas, for example) where they act more like
 short dipoles.

My question is:

Does NEC apply at least to some helical antennas, and any
benchmark solutions have been done to quantify how acurate the NEC solutions
are for helical antennas?

Feng

On Aug 8, 7:56, builder#064#cais.com%INTERNET_at_email.mot.com wrote:
> Subject: Re: Helical Antennas
> My masters thesis was a study of helical antennas, and the building of a
> prototype helical array (hooray for me ...). I found that NEC was 100%
> unreliable for helical antennas in both the so-called axial and normal
> modes. It has to do with the fact that the helical antenna acts as a
> waveguide structure that does not lend itself to NEC-like modeling. Kraus
> and some others tried to characterize helical antenna gain using NEC-like
> methods (actually closed form solutions), resulting in gross
> overestimates. Some really good work was done by Aerospace Corp (King and
> Wong) in the 1970's (?).
>
> On Wed, 7 Aug 1996, Mike Slater wrote:
>
> > I would appreciate any information pertaining to
> > helical antenna performance using NEC. I have heard
> > some remarks about NEC not being reliable, however,
> > I have not been able to find any literature,
> > results etc. that support or refute these claims.
> > If anyone has any info/suggestions/links I would
> > greatly appreciate any information.
> >
> > Thank you.
> >
> >
> > Mike Slater
> > mike_s_at_ece.concordia.ca
> > mike_s_at_pils.com
> >
> >
>
>
>-- End of excerpt from builder#064#cais.com%INTERNET_at_email.mot.com

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