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Spherical radiation pattern
There has been some "talk" that the spherical radiation pattern shown
via Poynting's vector is impossible or just a theoretical thing. There are many things that point to this such as point radiatiion as well as not being a realistic concept. I offer the following as an opposite aproach for the news group. First, I rely on the basic radiator as being in equilibrium which naturally points to a full wave length or reference to one period. Secondly, I point to a radiator as being the circuit of a tank circuit which is essentially perpetual motion if one removes the frictional aspect. Thus the approach by Maxwell is the ultimate point of maximum efficiency where all forces are accounted for and ALL contribute to radiation. From the above it is natural that a radiator is tipped to equal the outside vectors of the arbitrary boundary which are gravity and the Coriolis effect. We then have to allow the radiator to have near zero resistiveness such that all input power is used solely for radiation ( super cooled I suppose) From this approach we can state that, in the limit of zero resistance all power is converted into radiation! Thus if we have a radiator of one WL that is tipped in space and of near zero resistance in the impedance metric we will then attain a spherical radiation pattern as with Poynting's vector and thus a demonstration of point radiation together with further evidence that radiation is of a particle and not one of waves. By the way, since the phenomina of radiation is created solely by the electo-magnetic and electro-static fields per the tank circuit it becomes very clear that radiation is not continuous but in "packets or "pulses" because of the momentary stop as shown at the center of a sine wave. When I get back I look forward with interest how the group tries to counter above with presently known facts or the common retreat to insults or just rest comfortably assured that the prior postings explain all. See you all later and have a great week end |
Spherical radiation pattern
On Sep 11, 11:47*am, Art Unwin wrote:
There has been some "talk" that the spherical radiation pattern shown via Poynting's vector is impossible or just a theoretical thing. etc etc Quoting from John Kraus' well-respected textbook "Antennas For All Applications," 3rd edition, page 74: "Although the isotropic source is convenient in theory, it is not a physically realizable type. Even the simplest antennas have directional properties, i.e., they radiate more energy is some directions than in others." The Poynting vector does not apply only to isotropic sources. Here is a link to a simple definition: http://www.britannica.com/EBchecked/...oynting-vector .. It doesn't have to describe a perfect sphere. And in fact for practical, physical antennas it never does so. FYI, Art, nowhere in that textbook does Kraus write anything about your equilibrium, tipping, Coriolis effect, or tank circuits, or their being germane to the proper understanding and/or functioning of antennas. RF |
Spherical radiation pattern
"Art Unwin" wrote in message ... There has been some "talk" that the spherical radiation pattern shown via Poynting's vector is impossible or just a theoretical thing. There are many things that point to this such as point radiatiion as well as not being a realistic concept. I offer the following as an opposite aproach for the news group. of course you will... that doesn't make it right, or even logical. First, I rely on the basic radiator as being in equilibrium which naturally points to a full wave length or reference to one period. only in your brain since none of us understand your constantly changing explanation of what equilibrium is. Secondly, I point to a radiator as being the circuit of a tank circuit which is essentially perpetual motion if one removes the frictional aspect. ah, perpetual motion, now we are getting somewhere! Thus the approach by Maxwell is the ultimate point of maximum efficiency where all forces are accounted for and ALL contribute to radiation. maxwell's equations have nothing about gravity, the weak force, or the strong force, or efficiency included in them... From the above it is natural that a radiator is tipped to equal the outside vectors of the arbitrary boundary which are gravity and the Coriolis effect. the Coriolis effect is not a vector nor a force, it is a method of explaining what someone on a rotating sphere thinks they see... purely a figment of your imagination. We then have to allow the radiator to have near zero resistiveness such that all input power is used solely for radiation ( super cooled I suppose) From this approach we can state that, in the limit of zero resistance all power is converted into radiation! this one statement may contain some small smidgen of reality... you are slipping art! Thus if we have a radiator of one WL that is tipped in space and of near zero resistance in the impedance metric we will then attain a spherical radiation pattern as with Poynting's vector and thus a demonstration of point radiation together with further evidence that radiation is of a particle and not one of waves. nope, sorry, still won't work. it will still have the distorted doughnut pattern. By the way, since the phenomina of radiation is created solely by the electo-magnetic and electro-static fields per the tank circuit it becomes very clear that radiation is not continuous but in "packets or "pulses" because of the momentary stop as shown at the center of a sine wave. you have been listening to that other kook too much and have picked up his signature pulses... next you'll be talking about speakers and pressure wave interference to explain your equilibrium. When I get back I look forward with interest how the group tries to counter above with presently known facts or the common retreat to insults or just rest comfortably assured that the prior postings explain all. See you all later and have a great week end insults are so much more fun than trying to educate the insane! |
Spherical radiation pattern
On Sep 11, 1:04*pm, "Dave" wrote:
"Art Unwin" wrote in message ... There has been some "talk" that the spherical radiation pattern shown via Poynting's vector is impossible or just a theoretical thing. There are many things that point to this such as point radiatiion as well as not being a realistic concept. I offer the following as an opposite aproach for the news group. of course you will... that doesn't make it right, or even logical. First, I rely on the basic radiator as being in equilibrium which naturally points to a full wave length or reference to one period. only in your brain since none of us understand your constantly changing explanation of what equilibrium is. Secondly, I point to a radiator as being the circuit of a tank circuit which is essentially perpetual motion if one removes the frictional aspect. ah, perpetual motion, now we are getting somewhere! Thus the approach by Maxwell is the ultimate point of maximum efficiency where all forces are accounted for and ALL contribute to radiation. maxwell's equations have nothing about gravity, the weak force, or the strong force, or efficiency included in them... From the above it is natural that a radiator is tipped to equal the outside vectors of the arbitrary boundary which are gravity and the Coriolis effect. the Coriolis effect is not a vector nor a force, it is a method of explaining what someone on a rotating sphere thinks they see... purely a figment of your imagination. We then have to allow the radiator to have near zero resistiveness such that all input power is used solely for radiation ( super cooled I suppose) From this approach we can state that, in the limit of zero resistance all power is converted into radiation! this one statement may contain some small smidgen of reality... you are slipping art! Thus if we have a radiator of one WL that is tipped in space and of near zero resistance in the impedance metric we will then attain a spherical radiation pattern as with Poynting's vector and thus a demonstration of point radiation together with *further evidence that radiation is of a particle and not one of waves. nope, sorry, still won't work. *it will still have the distorted doughnut pattern. By the way, since the phenomina of radiation is created solely by the electo-magnetic and electro-static fields per the tank circuit it becomes very clear that radiation is not continuous but in "packets or "pulses" because of the momentary stop as shown at the center of a sine wave. you have been listening to that other kook too much and have picked up his signature pulses... next you'll be talking about speakers and pressure wave interference to explain your equilibrium. When I get back I look forward with interest how the group tries to counter above with presently known facts or the common retreat to insults or just rest comfortably assured that the prior postings explain all. See you all later and have a great week end insults are so much more fun than trying to educate the insane! David The idea is accountability for all forces. If you model for 100% radiation without losses you get a spherical pattern, no doubt about it. With respect to the choice of a WL radiator this is because it represents a period which classical physics demand. If one chooses 1/2 WL then you are using a fudge factor since one cannot avoid overshoot or the use of time just to obtain an impedance that mankind feel is better. Overshoot is a matter of correction by a circuit with the correction getting smaller and smaller but always with the inevitable corrections This then allows the cross over point of a sine wave to aproach, but never arrive, at the center representing a 1/2 WL. Now I have modeled the above aiming for zero for a resistive value in the impedance because that is the way programs are set up ,which is fine by me, as it supplies a truly spherical pattern just prior to the pattern moving away from a transmit to a recieve function On a separate note. Just because something is not mentioned in a book does not provide mention of such points to be false, only to the fact that the author has not fully completed his studies. There is no such thing of a book that explains all in it entirety, only different versions of plaguerisation, Failing that it shows that the ham fraternity considers "all is known" about radiation and complely discardes the notion of current possibly being ABOVE the surface of a radiator when the environment allows it to happen or even the presence of negative impedance with respect to a element with a time varying field e.t.c. otherwise it would be mentioned in a book Ofcourse there will be protests that certain things such as zero resistance cannot be otherwise electrical laws will have to be modified! Well that has proved to be normal when looking at history so shall we suppres it? |
Spherical radiation pattern
On Sep 11, 1:04*pm, "Dave" wrote:
"Art Unwin" wrote in message ... There has been some "talk" that the spherical radiation pattern shown via Poynting's vector is impossible or just a theoretical thing. There are many things that point to this such as point radiatiion as well as not being a realistic concept. I offer the following as an opposite aproach for the news group. of course you will... that doesn't make it right, or even logical. First, I rely on the basic radiator as being in equilibrium which naturally points to a full wave length or reference to one period. only in your brain since none of us understand your constantly changing explanation of what equilibrium is. Secondly, I point to a radiator as being the circuit of a tank circuit which is essentially perpetual motion if one removes the frictional aspect. ah, perpetual motion, now we are getting somewhere! Thus the approach by Maxwell is the ultimate point of maximum efficiency where all forces are accounted for and ALL contribute to radiation. maxwell's equations have nothing about gravity, the weak force, or the strong force, or efficiency included in them... From the above it is natural that a radiator is tipped to equal the outside vectors of the arbitrary boundary which are gravity and the Coriolis effect. the Coriolis effect is not a vector nor a force, it is a method of explaining what someone on a rotating sphere thinks they see... purely a figment of your imagination. We then have to allow the radiator to have near zero resistiveness such that all input power is used solely for radiation ( super cooled I suppose) From this approach we can state that, in the limit of zero resistance all power is converted into radiation! this one statement may contain some small smidgen of reality... you are slipping art! Thus if we have a radiator of one WL that is tipped in space and of near zero resistance in the impedance metric we will then attain a spherical radiation pattern as with Poynting's vector and thus a demonstration of point radiation together with *further evidence that radiation is of a particle and not one of waves. nope, sorry, still won't work. *it will still have the distorted doughnut pattern. By the way, since the phenomina of radiation is created solely by the electo-magnetic and electro-static fields per the tank circuit it becomes very clear that radiation is not continuous but in "packets or "pulses" because of the momentary stop as shown at the center of a sine wave. you have been listening to that other kook too much and have picked up his signature pulses... next you'll be talking about speakers and pressure wave interference to explain your equilibrium. When I get back I look forward with interest how the group tries to counter above with presently known facts or the common retreat to insults or just rest comfortably assured that the prior postings explain all. See you all later and have a great week end insults are so much more fun than trying to educate the insane! That appears to be true. However I have always used Bernollis experiments with liquid as being synonamous with current flow. So to mention Bernolles findings to the question of Eddy flow appears to me to have some merit., Introduction of pressure in both liquids, current flow and air flow I would consider having some merit. I once mentioned the similarity of a mechanical pump which is designed around Bernollies experiments producing the same deflections that we see with changing cross sections of electrical conductors, which then must produce cavitation and thus eddy curwrents. Roy instantly pushed me aside on that one saying the functions are different which immediately declares the Standard forces theory as nonsense. ( Sorry about that Einstein) Gotta go. Excuse me plse |
Spherical radiation pattern
On Sep 11, 1:55*pm, Art Unwin wrote:
The idea is accountability for all forces. If you model for 100% radiation without losses you get a spherical pattern, no doubt about it. With respect to the choice of a WL radiator this is because it represents a period which classical physics demand. I did, see the link below. The pattern of a full-wave antenna is far from being spherical. http://i62.photobucket.com/albums/h8...CompareArt.jpg RF |
Spherical radiation pattern
Have a good vacation Art!
- 73 de Mike N3LI - |
Spherical radiation pattern
"Michael Coslo" wrote in message ... Have a good vacation Art! - 73 de Mike N3LI - .... and when you get back, let's see some proof that all this wacky 'new-age' theory is of any practical use to mankind. I'd be willing to bet, say, 100 UK pounds that Professor Unwin can't create an antenna in hardware that radiates isotropically, that is, over a whole sphere within, let's say +/-1 dB with respect to any chosen (but constant) polarisation. Anyone wish to up the ante? Chris PS: for those who may not be aware, there used to be someone else known as 'Professor Unwin' who was famed for talking in gobbledygook http://www.stanleyunwin.com/audio.htm |
Spherical radiation pattern
christofire wrote:
... and when you get back, let's see some proof that all this wacky 'new-age' theory is of any practical use to mankind. I'd be willing to bet, say, 100 UK pounds that Professor Unwin can't create an antenna in hardware that radiates isotropically, that is, over a whole sphere within, let's say +/-1 dB with respect to any chosen (but constant) polarisation. Anyone wish to up the ante? Chris I'd be glad to, but there's no way to prove it. Measurement accuracy and repeatability just aren't that good, especially if you're trying to do a full 3D measurement. The closest I've seen to a 3D measurement system actually measured just one hemisphere. It was at what used to be NRAD (Naval Research and Development center) and before that NOSC in San Diego, consisting of a large (100 foot diameter if I recall correctly) rotating circular platform with a semicircular arch overhead. By rotating the platform and moving the detector along the arch, a full hemispherical measurement could be made. The models were physical scale models of Navy ships having appropriately scaled antennas. Even then, though, engineers there told me that when the measured results differed from NEC computer model results, they tended to believe the computer results. It's extremely difficult to make highly, or even moderately, accurate field strength measurements. A while back I designed an antenna for a consulting job which was simply a two-sloping-radial ground plane made with fairly wide traces on a low-loss PC board. George Brown, the inventor of the ground plane antenna, had observed an omnidirectional pattern in the horizontal plane with only two radials, but the marketing department at RCA insisted on adding two more to make it look symmetrical before selling them. Hence the ubiquitous 4-radial design. (The pattern of the 4 radial version is more circular above and below the horizontal plane, but not by a whole lot.) Anyway, I was concerned that maybe the PCB or the relatively wide, flat conductors might have a detrimental impact on the pattern circularity, so I took it to a local lab that has a high quality anechoic chamber and ran the pattern. When the plot was finished, the lab technician muttered "Holy $/!%", hit the print button, grabbed a camera, and ran into the chamber to take a picture of the antenna. Then he went around to the other folks at the lab with the picture and plot. Seems that it was circular within about a dB, better than their $10k reference antenna. The prototype, by the way, was made with adhesive copper tape and an X-Acto knife and looked as crude as it was. I can't claim that the pattern was really better than their reference antenna because small differences in positioning of the feedline (even though decoupled), the antenna, and anything else in the chamber can easily cause a couple of dB of pattern deviation. Roy Lewallen, W7EL |
Spherical radiation pattern
On Sep 11, 2:37*pm, Art Unwin wrote:
On Sep 11, 1:04*pm, "Dave" wrote: "Art Unwin" wrote in message .... There has been some "talk" that the spherical radiation pattern shown via Poynting's vector is impossible or just a theoretical thing. There are many things that point to this such as point radiatiion as well as not being a realistic concept. I offer the following as an opposite aproach for the news group. of course you will... that doesn't make it right, or even logical. First, I rely on the basic radiator as being in equilibrium which naturally points to a full wave length or reference to one period. only in your brain since none of us understand your constantly changing explanation of what equilibrium is. Secondly, I point to a radiator as being the circuit of a tank circuit which is essentially perpetual motion if one removes the frictional aspect. ah, perpetual motion, now we are getting somewhere! Thus the approach by Maxwell is the ultimate point of maximum efficiency where all forces are accounted for and ALL contribute to radiation. maxwell's equations have nothing about gravity, the weak force, or the strong force, or efficiency included in them... From the above it is natural that a radiator is tipped to equal the outside vectors of the arbitrary boundary which are gravity and the Coriolis effect. the Coriolis effect is not a vector nor a force, it is a method of explaining what someone on a rotating sphere thinks they see... purely a figment of your imagination. We then have to allow the radiator to have near zero resistiveness such that all input power is used solely for radiation ( super cooled I suppose) From this approach we can state that, in the limit of zero resistance all power is converted into radiation! this one statement may contain some small smidgen of reality... you are slipping art! Thus if we have a radiator of one WL that is tipped in space and of near zero resistance in the impedance metric we will then attain a spherical radiation pattern as with Poynting's vector and thus a demonstration of point radiation together with *further evidence that radiation is of a particle and not one of waves. nope, sorry, still won't work. *it will still have the distorted doughnut pattern. By the way, since the phenomina of radiation is created solely by the electo-magnetic and electro-static fields per the tank circuit it becomes very clear that radiation is not continuous but in "packets or "pulses" because of the momentary stop as shown at the center of a sine wave. you have been listening to that other kook too much and have picked up his signature pulses... next you'll be talking about speakers and pressure wave interference to explain your equilibrium. When I get back I look forward with interest how the group tries to counter above with presently known facts or the common retreat to insults or just rest comfortably assured that the prior postings explain all. See you all later and have a great week end insults are so much more fun than trying to educate the insane! That appears to be true. However I have always used Bernollis experiments with liquid as being synonamous with current flow. So to mention Bernolles findings to the question of Eddy flow appears to me to have some merit., Introduction of pressure in both liquids, current flow and air flow I would consider having some merit. I once mentioned the similarity of a mechanical pump which is designed around Bernollies experiments producing the same deflections that we see with changing cross sections of electrical conductors, which then must produce cavitation and thus eddy curwrents. Roy instantly pushed me aside on that one saying the functions are different which immediately declares the Standard forces theory as nonsense. ( Sorry about that Einstein) Gotta go. Excuse me plse David Forgot to mention. Current would not be applied to the radiator itself but only to the sheathing of homogenous particles at rest.( ie neutrinos who are part of the family of Leptons but still remain as particles) This way with opposing forces in shear which includes the bending moment or twist of the Standard Force, the chemical adhesion is broken and the particle is elevated to achieve a straight line projection with spin. In this event all electrical laws lie intact and where the resistance is solely of that of radiation to which current is applied. |
Spherical radiation pattern
"Roy Lewallen" wrote in message ... christofire wrote: ... and when you get back, let's see some proof that all this wacky 'new-age' theory is of any practical use to mankind. I'd be willing to bet, say, 100 UK pounds that Professor Unwin can't create an antenna in hardware that radiates isotropically, that is, over a whole sphere within, let's say +/-1 dB with respect to any chosen (but constant) polarisation. Anyone wish to up the ante? Chris I'd be glad to, but there's no way to prove it. Measurement accuracy and repeatability just aren't that good, especially if you're trying to do a full 3D measurement. The closest I've seen to a 3D measurement system actually measured just one hemisphere. It was at what used to be NRAD (Naval Research and Development center) and before that NOSC in San Diego, consisting of a large (100 foot diameter if I recall correctly) rotating circular platform with a semicircular arch overhead. By rotating the platform and moving the detector along the arch, a full hemispherical measurement could be made. The models were physical scale models of Navy ships having appropriately scaled antennas. Even then, though, engineers there told me that when the measured results differed from NEC computer model results, they tended to believe the computer results. It's extremely difficult to make highly, or even moderately, accurate field strength measurements. A while back I designed an antenna for a consulting job which was simply a two-sloping-radial ground plane made with fairly wide traces on a low-loss PC board. George Brown, the inventor of the ground plane antenna, had observed an omnidirectional pattern in the horizontal plane with only two radials, but the marketing department at RCA insisted on adding two more to make it look symmetrical before selling them. Hence the ubiquitous 4-radial design. (The pattern of the 4 radial version is more circular above and below the horizontal plane, but not by a whole lot.) Anyway, I was concerned that maybe the PCB or the relatively wide, flat conductors might have a detrimental impact on the pattern circularity, so I took it to a local lab that has a high quality anechoic chamber and ran the pattern. When the plot was finished, the lab technician muttered "Holy $/!%", hit the print button, grabbed a camera, and ran into the chamber to take a picture of the antenna. Then he went around to the other folks at the lab with the picture and plot. Seems that it was circular within about a dB, better than their $10k reference antenna. The prototype, by the way, was made with adhesive copper tape and an X-Acto knife and looked as crude as it was. I can't claim that the pattern was really better than their reference antenna because small differences in positioning of the feedline (even though decoupled), the antenna, and anything else in the chamber can easily cause a couple of dB of pattern deviation. Roy Lewallen, W7EL Interesting stuff. I think one can get a good idea what's going on by measuring in the cardinal planes and some 45 degree cuts. It would soon become apparent whether the antenna warrants closer inspection. I recall seeing what you describe at NRAA and NOSC also at ASWE in Funtington, near Portsmouth GB. There they also had an aluminium 'sea' and copper scale models of most of the British fleet for checking the ELF to HF patterns (scaled conductivities). For the case in hand, though, there's no requirement for a ground plane (viz. 'spherical' in the title) so the resulting hardware antenna could be oriented in a number of different ways and rotated about a single axis for measurement. I've had experience of doing this with a Lindenblad array, and measuring axial ratio at the same time. I've also been aware of someone else's model, made using flexible PCB material formed into a cylinder, which outperformed the brass-tube-and-rod one we were working on! Feed-line radiation can easily be overcome by using a small oscillator and battery: tiny, stable ones are available nowadays. I'd be convinced if the protagonist managed a truly isotropic pattern at just one frequency. Chris |
Spherical radiation pattern
"Art Unwin" wrote in message ... On Sep 11, 2:37 pm, Art Unwin wrote: On Sep 11, 1:04 pm, "Dave" wrote: David Forgot to mention. Current would not be applied to the radiator itself but only to the sheathing of homogenous particles at rest.( ie neutrinos who are part of the family of Leptons but still remain as particles) This way with opposing forces in shear which includes the bending moment or twist of the Standard Force, the chemical adhesion is broken and the particle is elevated to achieve a straight line projection with spin. In this event all electrical laws lie intact and where the resistance is solely of that of radiation to which current is applied. ahhhh, thank you for a good laugh art... now you can go enjoy your vacation. i couldn't see you go without mentioning your magical levitating diamagnetic neutrinos just one more time. while you are gone try to figure out how my ferromagnetic antennas happen to work so well without your diamagnetic neutrinos to do their magical levitating and twisting for me. |
Spherical radiation pattern
On Sep 11, 6:36*pm, "Dave" wrote:
"Art Unwin" wrote in message ... On Sep 11, 2:37 pm, Art Unwin wrote: On Sep 11, 1:04 pm, "Dave" wrote: David Forgot to mention. Current would not be applied to the radiator itself but only to the sheathing of homogenous particles at rest.( ie *neutrinos who are part of the family of Leptons but still remain as particles) This way with opposing forces in shear which includes the bending moment or twist of the Standard Force, the chemical adhesion is broken and the particle is elevated to achieve a straight line projection with spin. In this event all electrical laws lie intact and where the resistance is solely of that of radiation to which current is applied. ahhhh, thank you for a good laugh art... now you can go enjoy your vacation. i couldn't see you go without mentioning your magical levitating diamagnetic neutrinos just one more time. *while you are gone try to figure out how my ferromagnetic antennas happen to work so well without your diamagnetic neutrinos to do their magical levitating and twisting for me. Maxwells laws are all about accountability for ALL forces involved. In non diamagnetic materials one cannot account for energy that provides hysteresis losses. Thus equilibrium cannot be quantisized.ie balance of vectors. If the energy movement or decay per unit of time can be resolved then Maxwell's laws can be modified to include losses, such that all forces are accounted for. Until then Maxwells laws are governed by diamagnetic materials used as radiators as they do not retain hysteresis energy. As for "magic" one only has to play with magnets to see evidence of elevation together with the undeniability of twist. I welcome from you an alternative action that arises with a different application that deviates from The Standard Model per classical physics. As for Neutrinos, I prefer to allude to them as particles and not Leptons which describes particles emitted from the Sun. Unlike Cecil I cannot explain any properties that they gain or lose or what ever on their journey from the Sun.(Protons) Thus I am comfortable with the term "particles" which do not suggest that "neutrinos" cannot and do not change properties during their journey. Especially in the light of present thinking at CERN that such particles can penetrate to the other side of Earth when they cannot even break the glass of a CRT which they impinge upon. |
Spherical radiation pattern
On Fri, 11 Sep 2009 23:32:39 +0100, "christofire"
wrote: I'd be convinced if the protagonist managed a truly isotropic pattern at just one frequency. Hi Chris, Half-Isotropic (if you allow for total field - you didn't specify and any protoplasm could game that loose specification) at: http://www.qsl.net/kb7qhc/antenna/In...-1%20Field.gif The design has been kicking around for 10+ years now at that link, and not even original when I posted it. As for gaming the lack of polarization spec, I might simply offer that it doesn't matter - if you use an isotropic detecting antenna to measure the field of this antenna model in the link. For that isotropic detecting antenna, I would offer a golf-ball lump of coal and a thermistor. 73's Richard Clark, KB7QHC |
Spherical radiation pattern
"Richard Clark" wrote in message ... On Fri, 11 Sep 2009 23:32:39 +0100, "christofire" wrote: I'd be convinced if the protagonist managed a truly isotropic pattern at just one frequency. Hi Chris, Half-Isotropic (if you allow for total field - you didn't specify and any protoplasm could game that loose specification) at: http://www.qsl.net/kb7qhc/antenna/In...-1%20Field.gif The design has been kicking around for 10+ years now at that link, and not even original when I posted it. As for gaming the lack of polarization spec, I might simply offer that it doesn't matter - if you use an isotropic detecting antenna to measure the field of this antenna model in the link. For that isotropic detecting antenna, I would offer a golf-ball lump of coal and a thermistor. 73's Richard Clark, KB7QHC Well the title of the thread is 'Spherical radiation pattern' and I interpret that as meaning a far-field pattern that is uniform (within the 2 dB margin I offered) in respect of the transverse electric, or transverse magnetic, field strength, or the resulting power-flux density, over a whole sphere. I'm not sure what you mean by 'total field' in respect of a far-field pattern - all induction components should be insignificant including any 'cross-field' longitudinal ones. Also, my wager is in respect of a hardware antenna being built, not an NEC model. Regarding your lump of coal and a thermistor - how would you connect the thermistor? Surely that would impose some kind of polarisation however it was done ...? Chris |
Spherical radiation pattern
"christofire" wrote in message ... "Richard Clark" wrote in message ... On Fri, 11 Sep 2009 23:32:39 +0100, "christofire" wrote: I'd be convinced if the protagonist managed a truly isotropic pattern at just one frequency. Hi Chris, Half-Isotropic (if you allow for total field - you didn't specify and any protoplasm could game that loose specification) at: http://www.qsl.net/kb7qhc/antenna/In...-1%20Field.gif The design has been kicking around for 10+ years now at that link, and not even original when I posted it. As for gaming the lack of polarization spec, I might simply offer that it doesn't matter - if you use an isotropic detecting antenna to measure the field of this antenna model in the link. For that isotropic detecting antenna, I would offer a golf-ball lump of coal and a thermistor. 73's Richard Clark, KB7QHC Well the title of the thread is 'Spherical radiation pattern' and I interpret that as meaning a far-field pattern that is uniform (within the 2 dB margin I offered) in respect of the transverse electric, or transverse magnetic, field strength, or the resulting power-flux density, over a whole sphere. I'm not sure what you mean by 'total field' in respect of a far-field pattern - all induction components should be insignificant including any 'cross-field' longitudinal ones. Also, my wager is in respect of a hardware antenna being built, not an NEC model. Regarding your lump of coal and a thermistor - how would you connect the thermistor? Surely that would impose some kind of polarisation however it was done ...? Chris .... Oops, scratch that last bit - my mind must have been elsewhere! Of course you'd just drill a hole in it. Thinking about your lump of coal reminded me about the kinds of antenna used in radiation hazard meters, often three short dipoles mounted mutually perpendicularly, each with some kind of bolometer element at its centre. If one didn't care about polarisation then perhaps a similar arrangement could be used to transmit with a near-isotropic pattern, but that wouldn't be an efficient solution for communication. No, the challenge for Art Unwin, should he wish to put his money where his mouth (keyboard) is, is create and demonstrate a hardware antenna that exhibits a spherical radiation pattern in respect of a single polarisation. That would be useful. What is the red line in the pattern to which you gave the link? Chris |
Spherical radiation pattern
christofire wrote:
I'd be willing to bet, say, 100 UK pounds that Professor Unwin can't create an antenna in hardware that radiates isotropically, ... For those types of proof, it is impossible to prove a negative. It would be akin to the police knocking on your door and demanding that you prove that you are not a terrorist. The onus of logical proof is upon the one who makes the positive assertion. -- 73, Cecil, IEEE, OOTC, http://www.w5dxp.com |
Spherical radiation pattern
"Cecil Moore" wrote in message ... christofire wrote: I'd be willing to bet, say, 100 UK pounds that Professor Unwin can't create an antenna in hardware that radiates isotropically, ... For those types of proof, it is impossible to prove a negative. It would be akin to the police knocking on your door and demanding that you prove that you are not a terrorist. The onus of logical proof is upon the one who makes the positive assertion. -- 73, Cecil, IEEE, OOTC, http://www.w5dxp.com The one who has made the positive assertion is the one who has claimed that by his new theory an antenna can be made that has a spherical radiation pattern. I don't believe in the theory as he has laid out and I don't believe that such an antenna can be built and demonstrated. My wager is in respect of whether or not the protagonist can build and demonstrate such an antenna to back up his own positive assertion. It is in the nature of a challenge for him to take up if he wishes, and if he does then his bet will be in respect of his positive assertion, but, of course, he hasn't taken it up yet. If he doesn't take up the challenge then nothing new is proved - whichever way you care to interpret that. Chris |
Spherical radiation pattern
On Sep 12, 8:25*am, "christofire" wrote:
"Cecil Moore" wrote in message ... christofire wrote: I'd be willing to bet, say, 100 UK pounds that Professor Unwin can't create an antenna in hardware that radiates isotropically, ... For those types of proof, it is impossible to prove a negative. It would be akin to the police knocking on your door and demanding that you prove that you are not a terrorist. The onus of logical proof is upon the one who makes the positive assertion. -- 73, Cecil, IEEE, OOTC, *http://www.w5dxp.com The one who has made the positive assertion is the one who has claimed that by his new theory an antenna can be made that has a spherical radiation pattern. *I don't believe in the theory as he has laid out and I don't believe that such an antenna can be built and demonstrated. *My wager is in respect of whether or not the protagonist can build and demonstrate such an antenna to back up his own positive assertion. It is in the nature of a challenge for him to take up if he wishes, and if he does then his bet will be in respect of his positive assertion, but, of course, he hasn't taken it up yet. *If he doesn't take up the challenge then nothing new is proved - whichever way you care to interpret that. Chris Google... small efficient antenna steven best |
Spherical radiation pattern
"Art Unwin" wrote in message ... Google... small efficient antenna steven best and just what are we supposed to get out of all the links that it returns? that someone else built some other kinds of antennas that actually work? or that Dr Best knows more than you do? |
Spherical radiation pattern
On Sat, 12 Sep 2009 12:45:28 +0100, "christofire"
wrote: Well the title of the thread is 'Spherical radiation pattern' and I interpret that as meaning a far-field pattern that is uniform (within the 2 dB margin I offered) in respect of the transverse electric, or transverse magnetic, field strength, or the resulting power-flux density, over a whole sphere. Hi Chris, Well, simply put this antenna with its mirror image elements into free space and it accomplishes that quite easily. What is the red line in the pattern to which you gave the link? XYZ Axis. 73's Richard Clark, KB7QHC |
Spherical radiation pattern
On Sat, 12 Sep 2009 08:23:17 -0700 (PDT), Art Unwin
wrote: Google... small efficient antenna steven best http://www.cst.com/Content/Applications/Article/A+Small,+Efficient,+Linear-polarized+Omni-directional+Antenna The antenna fits inside a sphere of radius 0.0415 wavelengths. However, the antenna pattern is not spherical and more closely resembles the torus produced by a dipole than of an isotropic antenna. http://www.cst.com/CMS/images/article105/CPU05_047_600_481.jpg An isotropic approximation, which doesn't really qualify for the prize because the pattern is not polarization and phase insensitive. http://802.11junk.com/jeffl/antennas/isotropic/index.html -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Spherical radiation pattern
"Richard Clark" wrote in message ... On Sat, 12 Sep 2009 12:45:28 +0100, "christofire" wrote: Well the title of the thread is 'Spherical radiation pattern' and I interpret that as meaning a far-field pattern that is uniform (within the 2 dB margin I offered) in respect of the transverse electric, or transverse magnetic, field strength, or the resulting power-flux density, over a whole sphere. Hi Chris, Well, simply put this antenna with its mirror image elements into free space and it accomplishes that quite easily. Have you ever built one and measured its radiation pattern? Chris |
Spherical radiation pattern
On Sat, 12 Sep 2009 17:50:52 +0100, "christofire"
wrote: Have you ever built one and measured its radiation pattern? Hi Chris, Others have - the design is not unique to me and has been around for years. I modeled it to merely confirm those reports and that was rather simply accomplished. I have reported these results to interested parties here for the last 10 to 15 years. I am under no illusion that Art has ever used that data as a resource, otherwise it would undercut his claim of novelty. I've no doubt that other designs meeting your terse requirements could be rummaged up. I have no presumption that NEC fails for this one specific design that is ordinary in every regard to conventional modeling. At a minimum this is only 4 wires. As such, I am satisfied. 73's Richard Clark, KB7QHC |
Spherical radiation pattern
"Richard Clark" wrote in message ... On Sat, 12 Sep 2009 17:50:52 +0100, "christofire" wrote: Have you ever built one and measured its radiation pattern? Hi Chris, Others have - the design is not unique to me and has been around for years. I modeled it to merely confirm those reports and that was rather simply accomplished. I have reported these results to interested parties here for the last 10 to 15 years. I am under no illusion that Art has ever used that data as a resource, otherwise it would undercut his claim of novelty. I've no doubt that other designs meeting your terse requirements could be rummaged up. I have no presumption that NEC fails for this one specific design that is ordinary in every regard to conventional modeling. At a minimum this is only 4 wires. As such, I am satisfied. 73's Richard Clark, KB7QHC Good. Maybe this will encourage Art to have a go at my challenge by applying his own theories then. I had seen papers about inverted F antennas before (at an IEE or IET symposium some ten years ago), and I vaguely recall hearing that some manufacturers use them in mobile phones, but I'd never seen a pattern as uniform as the result of your simulation. Chris |
Spherical radiation pattern
"christofire" wrote in message ... "Richard Clark" wrote in message ... On Sat, 12 Sep 2009 17:50:52 +0100, "christofire" wrote: Have you ever built one and measured its radiation pattern? Hi Chris, Others have - the design is not unique to me and has been around for years. I modeled it to merely confirm those reports and that was rather simply accomplished. I have reported these results to interested parties here for the last 10 to 15 years. I am under no illusion that Art has ever used that data as a resource, otherwise it would undercut his claim of novelty. I've no doubt that other designs meeting your terse requirements could be rummaged up. I have no presumption that NEC fails for this one specific design that is ordinary in every regard to conventional modeling. At a minimum this is only 4 wires. As such, I am satisfied. 73's Richard Clark, KB7QHC Good. Maybe this will encourage Art to have a go at my challenge by applying his own theories then. I had seen papers about inverted F antennas before (at an IEE or IET symposium some ten years ago), and I vaguely recall hearing that some manufacturers use them in mobile phones, but I'd never seen a pattern as uniform as the result of your simulation. Chris art will never accept your challenge. its up to you to prove that his assertions are incorrect... and then get ignored as he continues to state the same things in many different forms. unless you can capture one of his diamagnetic levitating solar neutrinos and show that it doesn't sit on the antenna element and jump off when a pulse of current hits it you will never be believed... and even if you did capture one he would tell you it changed in flight from the sun. |
Spherical radiation pattern
On Sat, 12 Sep 2009 19:25:16 +0100, "christofire"
wrote: I had seen papers about inverted F antennas before (at an IEE or IET symposium some ten years ago), and I vaguely recall hearing that some manufacturers use them in mobile phones, but I'd never seen a pattern as uniform as the result of your simulation. Hi Chris, For a more academic treatment, the antenna is also known as the "U-Shaped Antenna of Shtrikman." His has three wires, my fourth wire is much like the J-Pole feed point attachment. Now, one proviso: this is not an isotropic in the sense of providing equal polarization at any angle. Nothing can accomplish that due to that requirement being impossible to meet (the so-called "hairy ball" problem). So, I simply resolved that with my carbon golf ball with its thermistor for detecting the Inverted F's total field to within the degree of less than 2dB variation over the shell surrounding the antenna. Good. Maybe this will encourage Art to have a go at my challenge by applying his own theories then. As I've shown, they are not his theories. Art doesn't have theories, they are illusions. Shtrikman's antenna has a model and a practical, real example that agree with one another in performance. The design is revealed and can be reproduced by anyone. No advanced math is demanded to perfect the results. No allusion to nuclear forces is required to explain any principle. Anyone can, and HAS built an antenna that Art can only mumble about. Perhaps I am mislead about this mumble, having kill-filed him, as I see his contribution (sic) only through other's quotes; few of which are full quotes (I can understand why). This last week in my driving through rain city, I've seen a street corner beggar who has worked one particular intersection for a couple of years now. He has a weather protected laminated board describing his plea, and he wears goretex weather gear that I couldn't afford. He does have this hang-dog appearance and shambling shuffle tho'. What is one to believe when it comes to claims? Clearly money talks. Who knows? He may have a patented system and sells franchises. 73's Richard Clark, KB7QHC |
Spherical radiation pattern
"Richard Clark" wrote in message ... On Sat, 12 Sep 2009 19:25:16 +0100, "christofire" wrote: I had seen papers about inverted F antennas before (at an IEE or IET symposium some ten years ago), and I vaguely recall hearing that some manufacturers use them in mobile phones, but I'd never seen a pattern as uniform as the result of your simulation. Hi Chris, For a more academic treatment, the antenna is also known as the "U-Shaped Antenna of Shtrikman." His has three wires, my fourth wire is much like the J-Pole feed point attachment. Now, one proviso: this is not an isotropic in the sense of providing equal polarization at any angle. Nothing can accomplish that due to that requirement being impossible to meet (the so-called "hairy ball" problem). I had understood it to be impossible on the basis of normal physics but Art Unwin's claim wasn't clear in respect of polarisation. So, I simply resolved that with my carbon golf ball with its thermistor for detecting the Inverted F's total field to within the degree of less than 2dB variation over the shell surrounding the antenna. Now I understand what you meant by 'total field' - sum of powers of components in all polarisations. Good. Maybe this will encourage Art to have a go at my challenge by applying his own theories then. As I've shown, they are not his theories. Art doesn't have theories, they are illusions. Shtrikman's antenna has a model and a practical, real example that agree with one another in performance. The design is revealed and can be reproduced by anyone. No advanced math is demanded to perfect the results. No allusion to nuclear forces is required to explain any principle. Anyone can, and HAS built an antenna that Art can only mumble about. Perhaps I am mislead about this mumble, having kill-filed him, as I see his contribution (sic) only through other's quotes; few of which are full quotes (I can understand why). Shtrikman's antenna sounds interesting. I will look up references. This last week in my driving through rain city, I've seen a street corner beggar who has worked one particular intersection for a couple of years now. He has a weather protected laminated board describing his plea, and he wears goretex weather gear that I couldn't afford. He does have this hang-dog appearance and shambling shuffle tho'. What is one to believe when it comes to claims? Clearly money talks. Who knows? He may have a patented system and sells franchises. 73's Richard Clark, KB7QHC Over here we've recently been subjected to the phenomenon of 'Seasick Steve' - who 'started out with nothing and still has most of it left' but also has a substantial recording contract. What is one to believe, as you so rightly say? Chris |
Spherical radiation pattern
On Sun, 13 Sep 2009 02:08:20 +0100, "christofire"
wrote: I had understood it to be impossible on the basis of normal physics but Art Unwin's claim wasn't clear in respect of polarisation. Hi Chris, Black body radiators do qualify as Isotropic; and as Art has claimed high efficiencies for RF impracticalities, it must be for efficient Infrared emission. 73's Richard Clark, KB7QHC |
Spherical radiation pattern
"christofire" wrote ... Now I understand what you meant by 'total field' - sum of powers of components in all polarisations. Does one wave has many polarizations, or one antenna has many polarizations? Which one: transmitter or receiver? Could you teach me? A* |
Spherical radiation pattern
"Richard Clark" wrote in message ... On Sun, 13 Sep 2009 02:08:20 +0100, "christofire" wrote: I had understood it to be impossible on the basis of normal physics but Art Unwin's claim wasn't clear in respect of polarisation. Hi Chris, Black body radiators do qualify as Isotropic; and as Art has claimed high efficiencies for RF impracticalities, it must be for efficient Infrared emission. 73's Richard Clark, KB7QHC .... but are randomly polarised, and I'd expect communication between a randomly-polarised antenna and either a normal, polarised antenna or another randomly polarised one to be lossy in comparison with the unusual case. Nevertheless, the principle that heaters are highly efficient is an amusing, occasionally useful one - standby dissipation contributing to heating your house and all that. Chris |
Spherical radiation pattern
"christofire" wrote in message ... "Richard Clark" wrote in message ... On Sun, 13 Sep 2009 02:08:20 +0100, "christofire" wrote: I had understood it to be impossible on the basis of normal physics but Art Unwin's claim wasn't clear in respect of polarisation. Hi Chris, Black body radiators do qualify as Isotropic; and as Art has claimed high efficiencies for RF impracticalities, it must be for efficient Infrared emission. 73's Richard Clark, KB7QHC ... but are randomly polarised, and I'd expect communication between a randomly-polarised antenna and either a normal, polarised antenna or another randomly polarised one to be lossy in comparison with the unusual case. * That was meant to be 'the usual case' - I let the spell checker have its way without looking at the result! Nevertheless, the principle that heaters are highly efficient is an amusing, occasionally useful one - standby dissipation contributing to heating your house and all that. Chris |
Spherical radiation pattern
"Szczepan Białek" wrote in message ... "christofire" wrote ... Now I understand what you meant by 'total field' - sum of powers of components in all polarisations. Does one wave has many polarizations, or one antenna has many polarizations? Which one: transmitter or receiver? Could you teach me? A* You appear to have changed your identity from S* to A* ! The answers according to the physics that real-life radio communication depends upon, and was designed by, a A single EM wave is plane polarised. It is composed of a magnetic field H that acts in a direction perpendicular to the direction of propagation, the magnitude and sign of this field varying as a travelling wave in the direction of propagation, and an attendant electric field E that also acts in a direction perpendicular to the direction of propagation. The magnitude and sign of the electric field varies as a travelling wave, coherent and in phase with the magnetic field and the magnetic field is a direct consequence of current flowing in the transmitting antenna. The directions in which the H and E fields act, in the plane transverse to the direction of propagation, are mutually perpendicular and the direction in which the E field acts, by convention, defines the polarisation. Thus a single EM wave has a single, plane, polarisation. Different combinations of waves are possible such as circular polarisation and, more generally, elliptical polarisation, but these can always be resolved into orthogonal plane components. Simple antennas like straight-wire dipoles and loops transmit and respond to plane polarised EM waves. More complicated antennas can be made to transmit and receive circular polarisation of one sense or the other, and generally an antenna will tend to transmit or be sensitive to some combination of different plane polarisations. In addition to radiated EM waves, there are also induction fields in a region close to the antenna. In a system that contains no anisotropic material (e.g. magnetised ferrite), when the distance between transmitting and receiving antennas is at least tens of wavelengths, the principle of reciprocity applies. By this principle the properties of an antenna when transmitting are the same as when it is receiving - the properties including the polarisation, radiation pattern and terminal impedance. If you find any of this interesting, please don't believe what I've written here but go to a technical library (e.g. at a University) and look up the authoritative sources - books on antennas and propagation by Kraus, Jasik, Jordan and Balmain, Terman, etc. Please _do not_ respond here telling me or the group that EM waves are longitudinal and are not polarised. Chris |
Spherical radiation pattern
"christofire" wrote in message ... "Szczepan Białek" wrote in message ... "christofire" wrote ... Now I understand what you meant by 'total field' - sum of powers of components in all polarisations. Does one wave has many polarizations, or one antenna has many polarizations? Which one: transmitter or receiver? Could you teach me? A* You appear to have changed your identity from S* to A* ! The answers according to the physics that real-life radio communication depends upon, and was designed by, a A single EM wave is plane polarised. It is composed of a magnetic field H that acts in a direction perpendicular to the direction of propagation, the magnitude and sign of this field varying as a travelling wave in the direction of propagation, and an attendant electric field E that also acts in a direction perpendicular to the direction of propagation. The magnitude and sign of the electric field varies as a travelling wave, coherent and in phase with the magnetic field and the magnetic field is a direct consequence of current flowing in the transmitting antenna. The directions in which the H and E fields act, in the plane transverse to the direction of propagation, are mutually perpendicular and the direction in which the E field acts, by convention, defines the polarisation. Thus a single EM wave has a single, plane, polarisation. Different combinations of waves are possible such as circular polarisation and, more generally, elliptical polarisation, but these can always be resolved into orthogonal plane components. Simple antennas like straight-wire dipoles and loops transmit and respond to plane polarised EM waves. More complicated antennas can be made to transmit and receive circular polarisation of one sense or the other, and generally an antenna will tend to transmit or be sensitive to some combination of different plane polarisations. In addition to radiated EM waves, there are also induction fields in a region close to the antenna. In a system that contains no anisotropic material (e.g. magnetised ferrite), when the distance between transmitting and receiving antennas is at least tens of wavelengths, the principle of reciprocity applies. By this principle the properties of an antenna when transmitting are the same as when it is receiving - the properties including the polarisation, radiation pattern and terminal impedance. If you find any of this interesting, please don't believe what I've written here but go to a technical library (e.g. at a University) and look up the authoritative sources - books on antennas and propagation by Kraus, Jasik, Jordan and Balmain, Terman, etc. Please _do not_ respond here telling me or the group that EM waves are longitudinal and are not polarised. Chris .... but the libraries are probably closed today so, for an instant, online source you could do worse than visit http://www.globalsecurity.org/milita...icy/navy/nrtc/, download the NEETS module 'ELECTRONICS TECHNICIAN, VOLUME 07--ANTENNAS AND WAVE PROPAGATION ' and read it. It's based on the same, real world physics. Chris |
Spherical radiation pattern
On Sun, 13 Sep 2009 12:46:30 +0100, "christofire"
wrote: Does one wave has many polarizations, or one antenna has many polarizations? Which one: transmitter or receiver? Could you teach me? A* You appear to have changed your identity from S* to A* ! The answers according to the physics that real-life radio communication depends upon, and was designed by, a A much simpler, and compelling explanation: what you see is what you get. If it looks vertical, the polarization is vertical; If it looks horizontal, the polarization is horizontal. It thus stands to reason that if the radiator is U shaped you see both horizontal and vertical - hence the full sphere filled with radiation. This closes the simple answer, which of course drives a very lengthy explanation - there is no such thing as a free lunch: Now, I can well anticipate some wag pointing out that they are standing, looking at these "goal posts" edge on and see only the vertical supports. "There is no horizontal view - no horizontal polarization. It can't be isotropic!" Of course it can't; and yet the vertical radiation fills the null of the horizontal (and likewise, the horizontal fills the null of the vertical). Total field is spherical. What does this make of a tilted radiator? What you see is what you get. At some perspectives it looks goofy horizontal AND it looks goofy vertical. In other perspectives it just looks vertical. As Art might protest: "Never mind goofy, how much horizontal?" If we reduce this to a number of goofiness, a trig function would serve quite well. Most students who were trained in mechanics would recognize the method to deconstruct an angle into its two, XY, components. If the tilt were 45 degrees, in full view of that angle you must experience the single antenna as having two equal vertical and horizontal contributions to radiation. If it were tilted 30 degrees, obviously one polarization would dominate over the other. Ground would compound the issue, but would not negate the general principle. This last part returns us to the discussion of isotropism which encompasses the topic of Lambert's Law which is generally confined to a black body radiator (or the sun from a great distance as it fails to be isotropic in the near view, such as we have here on earth). Few here need concern themselves with this unless they are making patch antennas. However, within the discussion above, the topic of view, angle, and radiation contribution are wrapped up in Lambert and cosine. 73's Richard Clark, KB7QHC |
Spherical radiation pattern
"christofire" wrote ... "Szczepan Białek" wrote in message ... You appear to have changed your identity from S* to A* ! Sorry. Mistake (A is adjacent to S). The answers according to the physics that real-life radio communication depends upon, and was designed by, a A single EM wave is plane polarised. It is composed of a magnetic field H that acts in a direction perpendicular to the direction of propagation, the magnitude and sign of this field varying as a travelling wave in the direction of propagation, and an attendant electric field E that also acts in a direction perpendicular to the direction of propagation. The magnitude and sign of the electric field varies as a travelling wave, coherent and in phase with the magnetic field and the magnetic field is a direct consequence of current flowing in the transmitting antenna. But there is the second direct consequence. If the current oscilate at the ends is developed the very high voltage. The high voltage produce the electric field. So you can wrote: "the electric field is a direct consequence of voltage developed in the ends of the transmitting antenna". This electric field generate the magnetic field and so on. So the Hertz' dipole has the three sources of waves. The centre and the two ends. It seams that waves from the centre are mainly transverse and that from the ends mainly longitudinal. Long wire antennas have many sources. Directional patern is number source dependent. You do not like the word voltage. May be the better is polarity. R. Clark wrote: "Actually you have mixed up two different characteristics. Polarity and polarization are NOT the same thing. With RF radiation, the wave is constantly changing polarity (that is why the source of RF is called alternating current), but within the "line of sight" of the antenna, the polarization for a dipole is defined by its angle to the earth as viewed by the observer. If you see an horizontal dipole, it produces alternating polarities of waves with horizontal polarization. If you see a vertical dipole, it produces alternating polarities of waves with vertical polarization." The directions in which the H and E fields act, in the plane transverse to the direction of propagation, are mutually perpendicular and the direction in which the E field acts, by convention, defines the polarisation. Thus a single EM wave has a single, plane, polarisation. Different combinations of waves are possible such as circular polarisation and, more generally, elliptical polarisation, but these can always be resolved into orthogonal plane components. Simple antennas like straight-wire dipoles and loops transmit and respond to plane polarised EM waves. More complicated antennas can be made to transmit and receive circular polarisation of one sense or the other, and generally an antenna will tend to transmit or be sensitive to some combination of different plane polarisations. In addition to radiated EM waves, there are also induction fields in a region close to the antenna. In a system that contains no anisotropic material (e.g. magnetised ferrite), when the distance between transmitting and receiving antennas is at least tens of wavelengths, the principle of reciprocity applies. By this principle the properties of an antenna when transmitting are the same as when it is receiving - the properties including the polarisation, radiation pattern and terminal impedance. If you find any of this interesting, please don't believe what I've written here but go to a technical library (e.g. at a University) and look up the authoritative sources - books on antennas and propagation by Kraus, Jasik, Jordan and Balmain, Terman, etc. Do they use the vord voltage? Please _do not_ respond here telling me or the group that EM waves are longitudinal and are not polarised. EM waves by Heaviside are transverse. Now we should check if he was right. S* |
Spherical radiation pattern
On Sun, 13 Sep 2009 19:57:22 +0200, Szczepan Bia?ek
wrote: EM waves by Heaviside are transverse. Now we should check if he was right. You have confused the telegrapher's equations with propagation. Before you recite an authority, you really need to understand them. 73's Richard Clark, KB7QHC |
Spherical radiation pattern
"Szczepan Białek" wrote in message ... "christofire" wrote ... "Szczepan Białek" wrote in message ... You appear to have changed your identity from S* to A* ! Sorry. Mistake (A is adjacent to S). The answers according to the physics that real-life radio communication depends upon, and was designed by, a A single EM wave is plane polarised. It is composed of a magnetic field H that acts in a direction perpendicular to the direction of propagation, the magnitude and sign of this field varying as a travelling wave in the direction of propagation, and an attendant electric field E that also acts in a direction perpendicular to the direction of propagation. The magnitude and sign of the electric field varies as a travelling wave, coherent and in phase with the magnetic field and the magnetic field is a direct consequence of current flowing in the transmitting antenna. But there is the second direct consequence. If the current oscilate at the ends is developed the very high voltage. The high voltage produce the electric field. So you can wrote: "the electric field is a direct consequence of voltage developed in the ends of the transmitting antenna". This electric field generate the magnetic field and so on. So the Hertz' dipole has the three sources of waves. The centre and the two ends. It seams that waves from the centre are mainly transverse and that from the ends mainly longitudinal. Long wire antennas have many sources. Directional patern is number source dependent. You do not like the word voltage. May be the better is polarity. R. Clark wrote: "Actually you have mixed up two different characteristics. Polarity and polarization are NOT the same thing. With RF radiation, the wave is constantly changing polarity (that is why the source of RF is called alternating current), but within the "line of sight" of the antenna, the polarization for a dipole is defined by its angle to the earth as viewed by the observer. If you see an horizontal dipole, it produces alternating polarities of waves with horizontal polarization. If you see a vertical dipole, it produces alternating polarities of waves with vertical polarization." The directions in which the H and E fields act, in the plane transverse to the direction of propagation, are mutually perpendicular and the direction in which the E field acts, by convention, defines the polarisation. Thus a single EM wave has a single, plane, polarisation. Different combinations of waves are possible such as circular polarisation and, more generally, elliptical polarisation, but these can always be resolved into orthogonal plane components. Simple antennas like straight-wire dipoles and loops transmit and respond to plane polarised EM waves. More complicated antennas can be made to transmit and receive circular polarisation of one sense or the other, and generally an antenna will tend to transmit or be sensitive to some combination of different plane polarisations. In addition to radiated EM waves, there are also induction fields in a region close to the antenna. In a system that contains no anisotropic material (e.g. magnetised ferrite), when the distance between transmitting and receiving antennas is at least tens of wavelengths, the principle of reciprocity applies. By this principle the properties of an antenna when transmitting are the same as when it is receiving - the properties including the polarisation, radiation pattern and terminal impedance. If you find any of this interesting, please don't believe what I've written here but go to a technical library (e.g. at a University) and look up the authoritative sources - books on antennas and propagation by Kraus, Jasik, Jordan and Balmain, Terman, etc. Do they use the vord voltage? Please _do not_ respond here telling me or the group that EM waves are longitudinal and are not polarised. EM waves by Heaviside are transverse. Now we should check if he was right. S* Evidently not from 'the physics that real-life radio communication depends upon, and was designed by'. Who is A* ? ... the person who wrote: Does one wave has many polarizations, or one antenna has many polarizations? Which one: transmitter or receiver? Could you teach me? A* Chris |
Spherical radiation pattern
Art wrote:
"Thus if we have a radiator of one WL that is tipped in space and near zero resistance in impedance metric we will then attain a spherical radiation pattern with Poynting`s vector and thus a demonsration of point radiation together with further evidence that radiation is of particle and not of waves." No matter how Art`s words were combined, I don`t see in them any such evidence. Even Art agrees that Maxwell`s equations correctly produce answers to where the energy goes. The 1955 edition of Terman`s "Electronic and Radio Engineering" shows the radiation pattern of one WL of wire in Fig. 23-4 (b) on page 867. It consists of four lobes each making an angle of 54 degrees with the axis of the wire. The pattern deviates from a spherical pattern by a lot. So much for "equilibrium"! Cecil pointed out that in physics, electromagnetic radiation is treated with duality, using either particle theory or waves, whichever is more convenient for the problem at hand. Maxwell solved the problems of radiation using wave equations which are said to be four of the most influential equations in science. On page 864 of Terman`s 1955 opus he writes: "The laws governing such radiation are obtained by using Maxwell`s equations to express the fields associated with the wire; when this is done there is found to be a component, termed the radiated field, having a strength that varies inversely with distance. If Art would just absorb Terman`s chapter on "Antennas" I doubt he would write such nonsense. Best regards, Richard Harrison, KB5WZI |
Spherical radiation pattern
Użytkownik "Richard Clark" napisał w wiadomości ... On Sun, 13 Sep 2009 19:57:22 +0200, Szczepan Bia?ek wrote: EM waves by Heaviside are transverse. Now we should check if he was right. You have confused the telegrapher's equations with propagation. Before you recite an authority, you really need to understand them. It is commonly known: "Heaviside said that mathematics was an experimental science. He organised Maxwell's mathematical work into the four equations which we now call "Maxwell's Equations". Maxwell made the model of solid ether. The four equations by Heaviside is rather "fluid analogy". "Now Heaviside had the concept of the TEM Wave, which Kelvin and Preece did not. With these two formulae, he could give a gloss of mathematical style to his assertion that, properly treated, a slab of energy current could propagate at the speed of light without distortion. This assertion had massive practical implications, but Heaviside was obstructed for decades." From: http://www.ivorcatt.com/2810.htm S* |
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