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antenna physics question

On Dec 15, 3:47*am, Art Unwin wrote:
On Dec 10, 8:37*am, joe wrote:

Art Unwin wrote:
*I am sure you also know that only
units used by Mawell represent the path
to maximum efficiency in radiation as well as
the ratio of capacitance to inductance must be
*unity.
Art KB9MZ....xg

Art, You have just mentioned a constraint on antennas that I was not aware
of. *Specifically "the ratio of capacitance to inductance must be unity".

This is new to me. Please tell me how I go about making capacitance and
inductance equal so their ratio can be unity. How do you get the Farads and
Henries to cancel out, leaving a dimensionless number.

Can you give me some real world examples?

joe

Joe,
*a better insight to my thinking that may help
When a member has little or no reactance via cancellation you can use
V=I.R.
When R becomes exceedingly small the member reaches a critical point
and will oscillate
When this happens current increases dramatically which therefore
increases radiation. If you view the current curve on a dipole the
current is of cyclic form whereas in the case where critical
resistance is reached
the current flow is of a very high value pulse which also drops fairly
rapidly until it reaches a low point before it gets to the end of a
period.
When the element oscillates it has become a mechanical movement BELOW
the current path
and as can be seen by comparing to water flow
the raggednes in terms of cross sectional area of flow has createrd
eddy currents which in electrical terms is equal to displacement
current
as it is the creation of displacement current.or coefficient of
discharge
This states why magnetics as used *in non equilibrium structures such
as the Yagi cannot be as efficient as a Meander form which achieves
higher current which propels *or provides for radiation..
What propelled the notion of waves instead of particles is 1 they
ignored Gaussian thrust towards equilibrium and 2 turned to the
increase in current because of the mechanical "wave" action which only
provides change in amplitude which is not enough to provide an
acceleration of charge on a *particle resting on
water since that requires two vectors.( I say a resting particle where
as it was never clear what the "wave" was lifting or where it came
from. This because the force required to remove an electron from its
element habitat
required more force than that was available.
( Gravity is termed as the weaker force in the Std model)
The bottom line being, a radiating structure in equilibrium devoid of
reactance with low resistance is the only way current over and above
that supplied becomes available.
By the way the std yagi is not a closed circuit
as equilibrium requires because the half wave length floats, where as
a full wave or "period"
is consistent or in a steady state when "overshoot" occurs. Thus only
when it is resonant is it devoid of reactance which limits the
bandwidth. In the case of a Meander form
the magnetic field is not present in cyclic form
allowing for surface current flow for extended periods and is not
frequency dependant.
As I have stated before, with my antenna current distribution is via a
surge with rapid decay which is accepted in RC L circuitry.
Hope that clears things up for you
Regards
Art

yup, clear as mud with waves.

antenna physics question

The IEEE Standard Definitions Terms for Antennas (IEEE Std 145-1993)
provides no definition for 'antenna efficiency' per se. A definition
is provided for 'antenna efficiency of an aperture-type antenna' in
section 2.15 of the document. The definitions are in alphabetical
order so the definition describing the ratio of power radiated to
input power appears in section 2.308 which is titled 'radiation
efficiency' (notice the dimensional metadata).

These citations from IEEE Standard Definitions Terms for Antennas
clearly suggest claims of a universal formula and definition for
antenna efficiency are incorrect. Not everyone means the same although
they use the same name. This is why it is important to define or refer
to the definitions that are used.

antenna physics question

Registered User wrote:
The IEEE Standard Definitions Terms for Antennas (IEEE Std 145-1993)
provides no definition for 'antenna efficiency' per se.

So what?

The term is in common use and can by found in many textbooks on
electromagnetics in general and antennas in particular, several books by
the ARRL as well as on many technical web pages.

--
Jim Pennino

Remove .spam.sux to reply.

antenna physics question

On Dec 15, 3:29*pm, wrote:
Registered User wrote:
The IEEE Standard Definitions Terms for Antennas (IEEE Std 145-1993)
provides no definition for 'antenna efficiency' per se.

So what?

The term is in common use and can by found in many textbooks on
electromagnetics in general and antennas in particular, several books by
the ARRL as well as on many technical web pages.

--
Jim Pennino

Remove .spam.sux to reply.

so what?

antenna physics question

K1TTT wrote:
On Dec 15, 3:29Â*pm, wrote:
Registered User wrote:
The IEEE Standard Definitions Terms for Antennas (IEEE Std 145-1993)
provides no definition for 'antenna efficiency' per se.

So what?

The term is in common use and can by found in many textbooks on
electromagnetics in general and antennas in particular, several books by
the ARRL as well as on many technical web pages.

--
Jim Pennino

Remove .spam.sux to reply.

so what?

So the fact that a particular IEEE standard does not mention a term that
is in common use is irrelevant to the fact that the term is in common use.

--
Jim Pennino

Remove .spam.sux to reply.

antenna physics question

On Dec 15, 8:49*pm, wrote:
Registered User wrote:
On Wed, 15 Dec 2010 15:29:12 -0000, wrote:

Registered User wrote:
The IEEE Standard Definitions Terms for Antennas (IEEE Std 145-1993)
provides no definition for 'antenna efficiency' per se.

So what?

snip babble

The post concerning "a unique and unambigous definition" which "can be
found in any textbook on electromagnetics" and subsequent
back-pedaling appears to fit that model. Your "So what?" provides the
meh.

Yeah, the "back-pedaling" which consisted of changing "any textbook" to
"many textbooks".

And nowhere did I reference any standard, IEEE, ISO, or any other standards
body.

well, maybe you should have... after all, some of us do use things
written by those bodies. some of us help write and test those
standards. and it sure would be nice if we could refer to a standard
way of describing antenna performance.

antenna physics question

K1TTT wrote:
On Dec 15, 8:49Â*pm, wrote:
Registered User wrote:
On Wed, 15 Dec 2010 15:29:12 -0000, wrote:

Registered User wrote:
The IEEE Standard Definitions Terms for Antennas (IEEE Std 145-1993)
provides no definition for 'antenna efficiency' per se.

So what?

snip babble

The post concerning "a unique and unambigous definition" which "can be
found in any textbook on electromagnetics" and subsequent
back-pedaling appears to fit that model. Your "So what?" provides the
meh.

Yeah, the "back-pedaling" which consisted of changing "any textbook" to
"many textbooks".

And nowhere did I reference any standard, IEEE, ISO, or any other standards
body.

well, maybe you should have... after all, some of us do use things
written by those bodies. some of us help write and test those
standards. and it sure would be nice if we could refer to a standard
way of describing antenna performance.

If this is so important to you, I am sure you will be researching all
the electromagnetics textbooks, antenna texbooks, industry and trade
publications, the ARRL, the RSGB, manufacturers, and everyone else with
any interest in antennas to determine the "correct" usage and definition
of the terms in question, and submitting a draft proposal to the IEEE.

--
Jim Pennino

Remove .spam.sux to reply.