Thread: Yagi efficiency
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Old December 2nd 06, 07:04 AM posted to rec.radio.amateur.antenna
Jerry Martes Jerry Martes is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 173
Default Yagi efficiency


"John Smith" wrote in message
...
Jerry Martes wrote:
...
How do you define efficiency?

Jerry




Jerry:

You make that sound like such a simple question.

Antenna efficiency is a complicated and often misused figure.

All antennas suffer from losses. A simple horn antenna for example will
not be as efficient as a perfect aperture of the same size because of
phase offset. The real efficiency of an antenna combines impedance match
with other factors such as aperture and radiation efficiency to give the
overall radiated signal for a given input. The best and mostwidely used
expression of this efficiency is to combine overall efficiency with
directivity (of the antenna) and express the efficiency times directivity
as gain.


The above is NOT mine, but taken from the web...
http://www.tmcdesign.com/antenna%20c...nformation.htm

So, we need to know if we are discussing antenna efficiency, or radiation
efficiency, or the skin effect as related to the ether efficiency, etc.
grin

Good that you are asking him!

Regards,
JS


Hi John

It really *is* a simple question. Again, how is Efficienct being defined
for this investigation?? As you have written, that question has to be
answered by Art, the original poster, ?doesnt it?

I was a little embarrassed because that "definition" of gain in the
referenced site was really difficult for me to understand. I really admire
you guys who understand phrases like "phase offset" as related to
efficiency.

Jerry