Q. What is the optimum antenna type to give the maximum gain given a
fixed overall length of elements? Or, alternately, what's the minimum
amount of wire/tubing to give a specified gain? (Neglecting support
structures)
As an example, for a gain of 15 dBi, an 11 element Yagi appears to have
about the same gain as two stacked 6 element Yagis which collectively
use one more element. But what about collinears, V Beams, arrays of
different sized Yagis etc. etc.?
Just out of curiosity.

Alan

a parabolic reflector fed with a feedhorn. no 'elements', just a hole in a
pipe and a big curved plate. you need to define the parameters a bit more.
for instance with no reflectors or directors, just driven verticals you can
make lots of gain. phased array radars have no wire/tubing elements, just
holes in a plate each with its own transmitter/receiver. and how do you
count dishes, corner reflectors, and the ground? by changing the height of
an antenna you can drastically change the gain at some particular takeoff
angle, so maybe you want to restrict it to free space. an do you want
minimum element count, or total material length? a very long wire can
create high gain lobes, but may not be very useful if you are thinking of
something rotateable.

"Alan Peake" wrote in message
...
Q. What is the optimum antenna type to give the maximum gain given a fixed
overall length of elements? Or, alternately, what's the minimum amount of
wire/tubing to give a specified gain? (Neglecting support structures)
As an example, for a gain of 15 dBi, an 11 element Yagi appears to have
about the same gain as two stacked 6 element Yagis which collectively use
one more element. But what about collinears, V Beams, arrays of different
sized Yagis etc. etc.?
Just out of curiosity.

Alan

On 1 jul, 14:36, Alan Peake wrote:
Q. What is the optimum antenna type to give the maximum gain given a
fixed overall length of elements? Or, alternately, what's the minimum
amount of wire/tubing to give a specified gain? (Neglecting support
structures)
As an example, for a gain of 15 dBi, an 11 element Yagi appears to have
about the same gain as two stacked 6 element Yagis which collectively
use one more element. But what about collinears, V Beams, arrays of
different sized Yagis etc. etc.?
Just out of curiosity.

Alan

Hello Alan,

There is no optimum antenna design that fits everything. Some factors:
Center Frequency
Side lobe level requirements
Gain requirements
Available materials
Required bandwidth.
Design skills / Experience
Ease of production
Number of antennas to be produced,
Available volume
Sentimental
Environmental aspects
Visibility (think of covert antennas).

There are (physical) limitations on antenna gain and antenna size.
Antennas with high gain must have a size far above wavelength.
Reduction of side lobes with given gain also requires a larger
antenna.

Omni directional gain requires large vertical antenna structures.
Every 3 dB gain increase, requires double the (vertical) size.

Best regards,

Wim
PA3DJS
www.tetech.nl
don't forget to remove abc when replying directly.

On Jul 1, 11:05 am, Wimpie wrote:
On 1 jul, 14:36, Alan Peake wrote:

Q. What is the optimum antenna type to give the maximum gain given a
fixed overall length of elements? Or, alternately, what's the minimum
amount of wire/tubing to give a specified gain? (Neglecting support
structures)
As an example, for a gain of 15 dBi, an 11 element Yagi appears to have
about the same gain as two stacked 6 element Yagis which collectively
use one more element. But what about collinears, V Beams, arrays of
different sized Yagis etc. etc.?
Just out of curiosity.

Alan

Hello Alan,

There is no optimum antenna design that fits everything. Some factors:
Center Frequency
Side lobe level requirements
Gain requirements
Available materials
Required bandwidth.
Design skills / Experience
Ease of production
Number of antennas to be produced,
Available volume
Sentimental
Environmental aspects
Visibility (think of covert antennas).

There are (physical) limitations on antenna gain and antenna size.
Antennas with high gain must have a size far above wavelength.
Reduction of side lobes with given gain also requires a larger
antenna.

Omni directional gain requires large vertical antenna structures.
Every 3 dB gain increase, requires double the (vertical) size.

Best regards,

Wim
PA3DJSwww.tetech.nl
don't forget to remove abc when replying directly.

May I offer a rebuttal to your use of "size:" with respect to
radiators?
The addition of radiators and a time varying field to a Gaussian field
shows that a radiator can be any size,shape or elevation as long as it
is in equilibrium.
This is because the result of additions to Gauss's static law results
in the same law of Maxwell.
It can also be seen that any deviation from a straight line format
which creats lumped loading must be neutralized since
radiation is related to distributed loads L and C. Thus shape or size
is a determination of the neutralisation of lumped loads
while attaining equilibrium. With the above in hand it can be seen
that Foucault current generates a field that elevates particles that
have attained a weak magnetic field by entering the earths system
which provides for their rejection or ejection. Per Newtons Law the
weak forces
involved (Fermi) create an oscillation of the radiator which is a
mirror image of arriving impulses upon a radiuator with the same
natural resonance.
It is only convention that calls for an radiator to be straight of
which a helix antenna is an excellent example ,where a continuation of
rotation back to the originating point provides for a full circuit in
equilibrium si9nce added lumped loads are cancelled. Examples of the
foucault current was provided earlier on this forum when describing
the separation of scrap metal by Foucault current rejection. As with
Newton, Faraday Gauss etc all laws depend on the theme of equilibrium
within a boundary of a balanced universe and not on minute sections
thereof.
Have a great week end
Art

Art Unwin wrote:

...
May I offer a rebuttal to your use of "size:" with respect to
radiators?
The addition of radiators and a time varying field to a Gaussian field
shows that a radiator can be any size,shape or elevation as long as it
is in equilibrium.
This is because the result of additions to Gauss's static law results
in the same law of Maxwell.
It can also be seen that any deviation from a straight line format
which creats lumped loading must be neutralized since
radiation is related to distributed loads L and C. Thus shape or size
is a determination of the neutralisation of lumped loads
while attaining equilibrium. With the above in hand it can be seen
that Foucault current generates a field that elevates particles that
have attained a weak magnetic field by entering the earths system
which provides for their rejection or ejection. Per Newtons Law the
weak forces
involved (Fermi) create an oscillation of the radiator which is a
mirror image of arriving impulses upon a radiuator with the same
natural resonance.
It is only convention that calls for an radiator to be straight of
which a helix antenna is an excellent example ,where a continuation of
rotation back to the originating point provides for a full circuit in
equilibrium si9nce added lumped loads are cancelled. Examples of the
foucault current was provided earlier on this forum when describing
the separation of scrap metal by Foucault current rejection. As with
Newton, Faraday Gauss etc all laws depend on the theme of equilibrium
within a boundary of a balanced universe and not on minute sections
thereof.
Have a great week end
Art

Art:

This mysterious "equilibrium" (which I seem to have a bit of problem
getting my mind wrapped about), although you, seemingly, sum up a group
of properties with a single word, isn't this just "resonance"--with
respect to conductor length/width, capacitance to surrounding objects
and the shape/form of the magnetic field produced by antenna currents, etc?

However, a thought did come to my mind ... with the new technique of
"taking pictures" of light waves/particles--if a super-strong
electromagnet was pulsed in an enclosure of excitable gas(es), perhaps
we could see some unknown/yet-unseen phenomenon ...

However, you are speaking of resonance, aren't you? still-scratching-head

Regards,
JS

"John Smith" wrote in message
...
Art Unwin wrote:

...
May I offer a rebuttal to your use of "size:" with respect to
radiators?
The addition of radiators and a time varying field to a Gaussian field
shows that a radiator can be any size,shape or elevation as long as it
is in equilibrium.
This is because the result of additions to Gauss's static law results
in the same law of Maxwell.
It can also be seen that any deviation from a straight line format
which creats lumped loading must be neutralized since
radiation is related to distributed loads L and C. Thus shape or size
is a determination of the neutralisation of lumped loads
while attaining equilibrium. With the above in hand it can be seen
that Foucault current generates a field that elevates particles that
have attained a weak magnetic field by entering the earths system
which provides for their rejection or ejection. Per Newtons Law the
weak forces
involved (Fermi) create an oscillation of the radiator which is a
mirror image of arriving impulses upon a radiuator with the same
natural resonance.
It is only convention that calls for an radiator to be straight of
which a helix antenna is an excellent example ,where a continuation of
rotation back to the originating point provides for a full circuit in
equilibrium si9nce added lumped loads are cancelled. Examples of the
foucault current was provided earlier on this forum when describing
the separation of scrap metal by Foucault current rejection. As with
Newton, Faraday Gauss etc all laws depend on the theme of equilibrium
within a boundary of a balanced universe and not on minute sections
thereof.
Have a great week end
Art

Art:

This mysterious "equilibrium" (which I seem to have a bit of problem
getting my mind wrapped about), although you, seemingly, sum up a group of
properties with a single word, isn't this just "resonance"--with respect
to conductor length/width, capacitance to surrounding objects and the
shape/form of the magnetic field produced by antenna currents, etc?

However, a thought did come to my mind ... with the new technique of
"taking pictures" of light waves/particles--if a super-strong
electromagnet was pulsed in an enclosure of excitable gas(es), perhaps we
could see some unknown/yet-unseen phenomenon ...

However, you are speaking of resonance, aren't you?
still-scratching-head

Regards,
JS

no, he's not... its the cosmic equilibrium between his fictitious particles
and the attraction of them the diamagnetic materials that makes antennas
work... of course he can't explain why ferromagnetic materials also work as
antennas, but that hasn't stopped him from spewing his garbage all over this
group. if you keep scratching your head while you try to figure out what he
is talking about you will run out of hair before you even get to first base.

On Jul 1, 1:58 pm, John Smith wrote:
Art Unwin wrote:
...
May I offer a rebuttal to your use of "size:" with respect to
radiators?
The addition of radiators and a time varying field to a Gaussian field
shows that a radiator can be any size,shape or elevation as long as it
is in equilibrium.
This is because the result of additions to Gauss's static law results
in the same law of Maxwell.
It can also be seen that any deviation from a straight line format
which creats lumped loading must be neutralized since
radiation is related to distributed loads L and C. Thus shape or size
is a determination of the neutralisation of lumped loads
while attaining equilibrium. With the above in hand it can be seen
that Foucault current generates a field that elevates particles that
have attained a weak magnetic field by entering the earths system
which provides for their rejection or ejection. Per Newtons Law the
weak forces
involved (Fermi) create an oscillation of the radiator which is a
mirror image of arriving impulses upon a radiuator with the same
natural resonance.
It is only convention that calls for an radiator to be straight of
which a helix antenna is an excellent example ,where a continuation of
rotation back to the originating point provides for a full circuit in
equilibrium si9nce added lumped loads are cancelled. Examples of the
foucault current was provided earlier on this forum when describing
the separation of scrap metal by Foucault current rejection. As with
Newton, Faraday Gauss etc all laws depend on the theme of equilibrium
within a boundary of a balanced universe and not on minute sections
thereof.
Have a great week end
Art

Art:

This mysterious "equilibrium" (which I seem to have a bit of problem
getting my mind wrapped about), although you, seemingly, sum up a group
of properties with a single word, isn't this just "resonance"--with
respect to conductor length/width, capacitance to surrounding objects
and the shape/form of the magnetic field produced by antenna currents, etc?

However, a thought did come to my mind ... with the new technique of
"taking pictures" of light waves/particles--if a super-strong
electromagnet was pulsed in an enclosure of excitable gas(es), perhaps
we could see some unknown/yet-unseen phenomenon ...

However, you are speaking of resonance, aren't you? still-scratching-head

Regards,
JS

No. Resonance is a quality of equilibrium but equilibrium is not
necessarily a part of resonance.
For instance, a full wavelength corresponding to a period of
oscillation is a form in equilibrium
where as a fractional wavelength can be resonant but certainly in
equilibrium
This really ia at the bottom of Newtons law regarding action and
reaction where all forces around a point
must equal zero. For instance if we have a member that is carrying an
alternating current applying such law states that there is
no moving charge on the inside of the member and where all charges on
the surface are in static form. The same law is used to determine the
likes oif skin depth.Now I have a problem with fractional WL current
carrying members where the surface charges move to one end which
suggests a internally moving charge. This effect can be seen when
comparing a dipole with a quad where the dipole can create corona at
the ends as the charges pile up as they look for a place to go doing
the time space of one period
where as a quad is a full WL anmd in equilibrium.
Maxwells law is based on equilibrium which means it can accoun t for
what is known as the "week force" which Einstein searched for in vain
for his GUT theory., Its inclusion in the laws of the masters was by
mathematical derivitation where they could not devine it even tho it
is one of the basic four forces of the Universe, the CLASSICAL model.
Now with my adaptation of gauss';s law which provides a picture of
radiation the appearance of weak eddy currents give rise to this
unknown weak force. With computers which are based around equilibrium
and Maxwell and now my extension of Gaussian law will provide the
result of that weak force by placing a radiator tipped from right
angles to the earths surface since all inside of a gaussian field MUST
be in equilibrium. If you need more explanation just ask for it or get
hold of a physics professor who is not a ham!
Regards
Art
Art

Dave wrote:

...
no, he's not... its the cosmic equilibrium between his fictitious particles
and the attraction of them the diamagnetic materials that makes antennas
work... of course he can't explain why ferromagnetic materials also work as
antennas, but that hasn't stopped him from spewing his garbage all over this
group. if you keep scratching your head while you try to figure out what he
is talking about you will run out of hair before you even get to first base.



Actually, there is only one alternative--the ether ... something which I
wish they will explore with new techniques ... Something (ether) which
even Einstein acknowledged. However, why Art would "waltz" around
something which is already being explored/argued, and cloak that
"waltzing" in an unfamiliar term(s) is simply beyond me ... unless ones'
point is obsfucation.

Regards,
JS

Art Unwin wrote:

...
No. Resonance is a quality of equilibrium but equilibrium is not
necessarily a part of resonance.
For instance, a full wavelength corresponding to a period of
oscillation is a form in equilibrium
where as a fractional wavelength can be resonant but certainly in
equilibrium
This really ia at the bottom of Newtons law regarding action and
reaction where all forces around a point
must equal zero. For instance if we have a member that is carrying an
alternating current applying such law states that there is
no moving charge on the inside of the member and where all charges on
the surface are in static form. The same law is used to determine the
likes oif skin depth.Now I have a problem with fractional WL current
carrying members where the surface charges move to one end which
suggests a internally moving charge. This effect can be seen when
comparing a dipole with a quad where the dipole can create corona at
the ends as the charges pile up as they look for a place to go doing
the time space of one period
where as a quad is a full WL anmd in equilibrium.
Maxwells law is based on equilibrium which means it can accoun t for
what is known as the "week force" which Einstein searched for in vain
for his GUT theory., Its inclusion in the laws of the masters was by
mathematical derivitation where they could not devine it even tho it
is one of the basic four forces of the Universe, the CLASSICAL model.
Now with my adaptation of gauss';s law which provides a picture of
radiation the appearance of weak eddy currents give rise to this
unknown weak force. With computers which are based around equilibrium
and Maxwell and now my extension of Gaussian law will provide the
result of that weak force by placing a radiator tipped from right
angles to the earths surface since all inside of a gaussian field MUST
be in equilibrium. If you need more explanation just ask for it or get
hold of a physics professor who is not a ham!
Regards
Art
Art

Hmmm ... sounds to me of the magnetic component of the antenna current
reacting with, or acting upon, the ether and creating the rf wave
phenomenon (waves/particles/etc.) ... there are a millions ways,
perhaps, to refer to this, as yet unproven effect/affect, but this
theory has already been on the table for centuries ... discarded and
then reincarnated at least once ...

Regards,
JS

Art Unwin wrote:

With the above in hand it can be seen
that Foucault current generates a field that elevates particles that
have attained a weak magnetic field by entering the earths system
which provides for their rejection or ejection. Per Newtons Law the
weak forces
involved (Fermi) create an oscillation of the radiator which is a
mirror image of arriving impulses upon a radiuator with the same
natural resonance.

Hi Art -

You have a unique way of making simple notions seem utterly
ridiculous. :-)

ac6xg