wrote in message
oups.com...
So I guess the annular slot is the complement to a halo?


Since I think of a halo as a loop in a plane parallel to the ground, it is
difficult for me to make a comparison of it to a monopole antenna pattern.

My suggestion would be for you to re-define your needs. There are some
really good antenna designers contributing to this group.

I'm not the one designing the antenna. I'd build a collinear. I'm
just interested in the properties of the annular slot.

What I mean by "I guess the annular slot is the complement to a halo?"
is this:

A halo as I know it is a half wave or so loop broken opposite the
feedpoint and in a plane parallel to the ground. It has an
omnidirectional azimuth pattern but radiates horizontally polarized
radiation.

It seems that the annular slot is a slot in a plane parallel to the
ground, with an omnidirectional azimuth pattern, and vertically
polarized radiation.

So, is an annular slot antenna a halo cut out of a sheet?

73,
Dan
N3OX

On Mon, 17 Apr 2006 13:56:19 -0500, "Hi" no@spam wrote:

This is a horizontally powerized omni slot antenna.
http://tinyurl.com/kbwkf
Does anyone know if its possible to make a
vertically polerized omni slot antenna?
Matt

One can be made, but the slots have to be
oriented at a slant on the waveguide. The
trick is to make alternate slots radiate
the horizontal component of their slanted
polarization out of phase but have the
vertical component radiated in-phase. This
is a bit tricky and requires a detailed
knowledge of the standing-wave pattern inside
the waveguide at the frequencies of interest
(and therefore is left as an exercise for the
student).

Jim, K7JEB

This is a horizontally powerized omni slot antenna.
http://tinyurl.com/kbwkf
Does anyone know if its possible to make a
vertically polerized omni slot antenna?
Matt

One can be made, but the slots have to be
oriented at a slant on the waveguide. The
trick is to make alternate slots radiate
the horizontal component of their slanted
polarization out of phase but have the
vertical component radiated in-phase. This
is a bit tricky and requires a detailed
knowledge of the standing-wave pattern inside
the waveguide at the frequencies of interest
(and therefore is left as an exercise for the
student).

Do you know of any websites or books that might have further info on this?

Thanks.

Matt