On 3/26/2016 12:53 AM, Jeff Liebermann wrote:
On Fri, 25 Mar 2016 21:24:45 -0700, "Sal M. O'Nella"
wrote:

I don't know the correct definition, but my definition is an antenna array
with inline elements.
Those elements can be parasitic or driven. And they can be dipoles, quads,
triangles or whatever.

My definition of an antenna is a matching transformer which matched
the output impedance of a transmitter, with that of free space (377
ohms). Convention has it to name the antenna after the designer. In
this case, Shintaro Uda was the student assistant who designed the
antenna, while Hidetsugu Yagi was his university instructor. Uda
published a paper on the design in Japanese, which nobody seemed to
have noticed. A few years later, Yagi translated the paper into
English, which finally got some attention. Its publication resulted
in the antenna being called a Yagi antenna by the American press. Yagi
repeatedly reminded everyone that it was Uda who had designed the
antenna, and deserved the credit. However, the best that could be
done was the Yagi-Uda contraction, which is awkward and backwards.

http://what-is-what.com/what_is/Yagi_Uda_antenna.html
"Despite the fact that Hidetsugu Yagi never took credit for
the antenna's design, it was his name that the American press
used to refer to the concept."

http://www.radiocomms.com.au/content/industry/article/yagi-the-man-behind-the-antenna-647231587
"The technology is all down to Prof Hidetsugu Yagi and his
assistant Shintaro Uda; more to Uda than Yagi, in fact, so
strictly speaking the design should be known as the Uda antenna,
or at least Yagi-Uda."

Incidentally, I have an FM broadcast Yagi-Uda antenna on my roof that
was made by the Yagi-Uda Antenna Company (or something like that).
I'll see if I can find the documentation and post a copy.

Both of these pages were interesting, but hard to read. I don't get why
some pages use a light grey text. I suppose some don't have a problem
reading that, but I do, a *lot*. The other page intentionally added a
shadow to the text, not just the headings or links, making that page
even harder for me to read. I really don't get that either.

I found a few more pages on Yagi-Uda antennas and some derivatives. One
describes how to build a Quagi antenna where the driven element and the
reflector are loops. Seems that works pretty well getting similar
numbers to Yagi type antennas with more directors.

What I really need in an antenna, is something I can add to the ubiquiti
nanostation m900 loco I am using for Internet access. The internal
antenna is only 7.5 dBi. I see a Yagi which is 13 dBi but it seems to
be out of date. The current model is very fancy and is over $200. The
other one is only $33.

--

Rick