Thread: Yagi efficiency
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Old December 2nd 06, 03:47 PM posted to rec.radio.amateur.antenna
Jerry Martes Jerry Martes is offline
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First recorded activity by RadioBanter: Jul 2006
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Default Yagi efficiency


"Cecil Moore" wrote in message
. ..
Jerry Martes wrote:
Can you try again to teach me how efficiency is defined??


What kind of efficiency? antenna? beam? aperture?
overall? conduction-dielectric?

Balanis defines overall antenna efficiency as the
product of:

1. reflection (mismatch) efficiency
2. conduction efficiency
3. dielectric efficiency

He gives the conduction-dielectric efficiency as:

Rr/(RL + Rr)

where Rr is the radiation resistance and
RL is the (conduction + dielectric) losses

He gives beam efficiency as:

(Beam cone power)/(Total radiated power)

He also says for a 1-dimensional aperture as a
function of taper: "The aperture efficiency is
a maximum with no taper, while the beam efficiency
is a maximum with full taper."
--
73, Cecil http://www.w5dxp.com


Hi Cecil

How does Art define Efficiency for evaluating Yagi antennas?

Jerry