It's a wire beam antenna.

Take a two element yagi made of wire and fold it into a more compact form as shown on
the right. Now support the wires with six spreader arms bent upward into an inverted
umbrella shape as below and you have a hexagonal beam.
So, by just folding the wires, the beam is more compact and yet still performs as well
(even better for front/back) as a full size two element yagi beam.

This means you have a light weight structure that can be mounted on a push up mast in
a garden home sized backyard. It's an inexpensive way to clobber your old dipole, G5RV
or whatever, from a performance standpoint.
The best part is that you can nest  wires for several bands
into the inverted umbrella structure and achieve a multi
band antenna that performs well on all bands and all with
only one feed line. And no traps or tuning devices. You get
SWR across nearly all bands less than 2:1 and most of the
bands nearly 1:1. That is performance!

And on the right here's what a multi-band hexagonal beam
looks like with just the wires shown.

Actually, "hexbeam" is a trademarked term of Traffie
Technologies, the only commercial maker of the original
design of hexagonal beams. Despite the trademark, you will
find the term used widely on the web especially by builders
of homebrew hexagonal beams. Because of the trademark concerns, we refer to the beams in their generic sense as hexagonal beams as all use a
six arm spreader shape even though the wires are configured differently.

The shape of the original hexagonal beam and the Traffie HEX-BEAM is shown to the right and is slightly different from the shape shown above. It is
more like an M and a W when viewed looking down on it. The original design is referred to generally as the "classic." The "classic" design has all the
advantages of the broadband shape shown above but with a serious disadvantage that it is a more narrow in its frequency band. This means that the
performance peak is sharper and not as broad across the band.

The later design is referred to generally as the broadband hexagonal beam and because it was developed by G3TXQ, his call sign is generally
associated with it. Most builders of hexagonal beams now are using the broadband shape above.
You can get a fuller discussion of the two shapes
and indeed a comparison of modeling of them.
Classic hexagonal beam
wire shape
(This is the shape of the Traffie
HEX-BEAM)
What is a Hexbeam?
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