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.
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" <adpe...@nosspam.activ8.net.au> 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.
On 1 jul, 14:36, Alan Peake <adpe...@nosspam.activ8.net.au> 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 1 jul, 14:36, Alan Peake <adpe...@nosspam.activ8.net.au> 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>
>> ... >> 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.
> 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.
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 ...
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. :-)
