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Re: "Projector of the Sharpest Beam of Electric Waves"

 

Indeed, and I think I have most of them in my library.

Today, I had the foresight to grab both volumes of "Antenna Theory" from my office at work. Parasitic arrays are discussed in Volume 1, pp 402-406. Reference is made to a paper called "The Long Yagi-Uda Array" by R.J. Mailloux appearing in the IEEE Transactions on Antenna Propagation, Vol AP-14, pp 128-137, 1966 as well as "Optimization of the Yagi Array" by I.L. Morris, his doctoral dissertation from Harvard, 1965.

Sean


On Sun, Mar 14, 2021 at 03:12 PM, Dave Daniel wrote:
Collin was a somewhat prolific writer of text books about EM fields, propagation and antennas. I think he was the author or co-author of six or seven different books.
?
DaveD
EM slow waves

 


In a PM Kai mentioned "EM slow wave structures", something I'd never heard of. I started this as a reply to him, but decided it might be of more general interest to the list.

A perusal of 2 ft of EM monographs produced no more than a few hundred words in total on slow waves. The most illuminating was Weeks IIRC who noted that the phase and amplitude peaks of a plane wave do not coincide. Unfortunately Pozar does not have an index, so not very helpful and I don't have access to his papers on the subject. Thomas Lee said nothing which was a great surprise as he takes such delight in the subject and the associated arcana.

Google scholar did turn up a few things, but in a very different situation where there was a continuous conductor and they were inducing scattering by altering the dielecric constant of the substrate. The other examples were simply serpentine conductors.

Before I strayed from the strait and narrow path of petrology into the debauchery of reflection seismic research I spent a year with a polarizing light microscope and 54 thin sections for 6-8 hours a day. Anisotropic crystals have different propagation velocities in 2 or 3 directions. Accurately measuring those with the microscope is an art and skill of considerable merit in my view, but it has been completely displaced by other methods. The wonderful thing about the PLM is you can carry one in a car or truck and do an analysis in the middle of nowhere on the hood and get an immediate answer. This is of great value in exploration where it is very expensive and arduous to return to the location after taking samples and sending them to a lab for analysis. It had been my goal to go into minerals exploration, but at the time I graduated that field was completely dead. PhDs with 20 years of exploration experience were pounding the pavement looking for work. Not a lot of hope for a newly minted MS.

Later when I was in grad school at Austin studying reflection seismology I took considerable exception to the term "transverse anisotropy" as it was used in connection with isotropic layers with varying velocities in each layer of a series of thin layers (shales).

I should describe the "EM slow wave" as an example of a scattering matrix very similar to the "transverse anisotropy" of shales. The most detailed discussion I found in my library was in the context of electronically steered radar arrays. In that context I'd describe it as the inevitable consequence of a discrete array of emitters of finite dimensions. In a layered system it is a function of the layer thicknesses.

I have a Tek 11801 and SD-24 sampling head so I am well equipped for measuring femtosecond delays. As the step from the SD-24 is very broadband, constructing my hypothetical line of conductors with a dipole feed point in an asymmetric position relative to the ends is quite tractable. The biggest obstacle seems at present to be the relationship between the length ofand spacing of the conductors. However, if I use elastic yarn from the sewing supplies section at Walmart to support the conductors I should be able to simply make a line of some 40-50 elements and then vary the spacing by stretching the line.

I have additional 20 GHz SD-26 heads, which are SD-24s minus the 2x 19 ps rise time step generators, so I should be able to probe very well so long as I don't make some botch of the setup.

So if anyone else is crazy enough to be interested in this stuff I'd love to hear what you think would be a good experiment.

Have Fun!
Reg

Re: How do we build advertising revenue for QEX?

 

Hello,

I am, definitely, willing to promote the magazine on my Instagram for free.


Tam

--
With best regards
Tam HANNA

Enjoy electronics? Join 19k7 other followers by visiting the Crazy Electronics Lab at

Re: "Projector of the Sharpest Beam of Electric Waves"

 

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Collin was a somewhat prolific writer of text books about EM fields, propagation and antennas. I think he was the author or co-author of six or seven different books.

DaveD

On Mar 14, 2021, at 16:32, Sean Turner <[email protected]> wrote:

On that note, another book by Collin ("Antennas and Radiowave Propagation) that isn't in my work office has this to say about parasitic arrays:
Parasitic arrays have usually been designed by experimental methods because of the difficulty of calculating the mutual impedances, the element lengths, and the optimum spaces, since these parameters are all interrelated in a complex nonlinear way.
I certainly don't think discussing the possibility of coming up with an analytic proof is a waste of time, but such a proof will be hard to say the least.

Sean

On Sun, Mar 14, 2021 at 01:14 PM, David Kirkby wrote:
On Sun, 14 Mar 2021 at 01:47, Reginald Beardsley via <pulaskite=[email protected]> wrote:

If anyone knows of a rigorous proof that the Yagi-Uda is the "sharpest beam" I am *very* interested in reading it.? On inspection it seems plausible, but mathematics at that level is rather a black art to mere applied math people like me.

Thanks and..

Have Fun!
Reg
?
I find it extremely unlikely that such proof exists. You would of course need to start by defining what is the "sharpest beam". The diffraction limit puts a limit on the first sidelobe and some Yagi-Uda antennas have the first sidelobe approximately that.
?
I find it worrying that the ARRL no longer sell Lawson's book on Yagi-Uda antennas. It was an ARRL publication.? It was the book that taught me enough to write my own program to analyze the antenna. It is a fairly different concept to NEC. You could argue it give you an analytical expression for the far-field, as the far-field pattern depends on the self impedance of elements and the mutual impedance between them. But the formula for mutual impedance in Lawson's book makes the assumption the elements have zero diameter and are a half-wave long.
?
The National Bureau of Standards (NBS)? made lots of careful measurements on Yagi-Uda antennas. Lawson shows that one of them must be wrong - probably just a typo.
?
Dave
Re: "Projector of the Sharpest Beam of Electric Waves"

 

On Mar 14, 2021, at 17:43, Reginald Beardsley via groups.io <pulaskite@...> wrote:

Do *not* underestimate the power of "operational mathematics". Oliver Heaviside was correctly solving problems that the mathematicians couldn't solve for years before some of them were intrepid enough to prove why it worked. In the end, the development of the LaPlace transform eclipsed Heaviside. But Heaviside was not wrong and Churchill's text is very much an homage to that. It's also important to remember that "Maxwell's equations" as we know them are really "Heavyside's equations". Maxwell used quaternions. It was Heaviside who introduced Faraday's work in vector notation with the addition of Maxwell's inspired assumption that another equation was needed for symmetry.
An excellent history of the above is contained in Bruce R. Hunt’s “The Maxwellians”, which, IIRC, includes a comparison of Maxwell’s original equations and Heaviside’s final forms using vector calculus, as well as a rather complete history of the work done that eventually led to Maxwell’s work (including some very strange mechanical models used to visualize EM fields).

DaveD
Re: "Projector of the Sharpest Beam of Electric Waves"

 

Do *not* underestimate the power of "operational mathematics". Oliver Heaviside was correctly solving problems that the mathematicians couldn't solve for years before some of them were intrepid enough to prove why it worked. In the end, the development of the LaPlace transform eclipsed Heaviside. But Heaviside was not wrong and Churchill's text is very much an homage to that. It's also important to remember that "Maxwell's equations" as we know them are really "Heavyside's equations". Maxwell used quaternions. It was Heaviside who introduced Faraday's work in vector notation with the addition of Maxwell's inspired assumption that another equation was needed for symmetry.

In this case, consider a series of wires at uniform spacing orthogonal to the direction of propagation which are of uniform length with a dipole in place of the single elements at some point. The dipole and the lengths of the other elements are unspecified except that that they are all resonant at the same frequency. Such a line will divide the input equally in both directions when the dipole is excited.

This constitutes a transmission line. Rather different from normal models, but you can plug all the values in and calculate impedances, etc. If one then perturbs the elements on one side of the dipole such that it is highly reflective it starts to get interesting.

If one can show that the radiation off axis to the direction of propagation along such a transmission line is a minimum at the resonant frequency, then one has proved that it is the "sharpest beam". I don't know how to do that, but I suspect someone who is better at EM than I can. I suspect it is obvious to a very select few.

From there it is simply a matter of approximating the effects of truncation. That in the 1920's could *only* be done by empirical methods. But the insight needed to recognize that such a structure constitutes a transmission line and could be used in truncated form as an antenna is without question world class. Or in Reg speak, "mondo cool!"

A big thanks to Kaz for including this paper in the issue. This has truly been great fun to contemplate. I'd been looking for a paper in QEX about which I had something at least semi-sensible to say. This was just close enough to my home turf of elastic wave propagation.

If my conjectures above are correct, then it seems likely that there may be some obscure papers by Yagi, Uda or both which are only available in Japanese. If anyone can read Japanese and has access to the Japanese literature, I think it would be fitting and proper to have that translated and published for more general access and to properly credit what is without question an exceptional piece of work.

Have Fun!
Reg
On Sunday, March 14, 2021, 03:33:23 PM CDT, Sean Turner <[email protected]> wrote:


On that note, another book by Collin ("Antennas and Radiowave Propagation) that isn't in my work office has this to say about parasitic arrays:
Parasitic arrays have usually been designed by experimental methods because of the difficulty of calculating the mutual impedances, the element lengths, and the optimum spaces, since these parameters are all interrelated in a complex nonlinear way.
I certainly don't think discussing the possibility of coming up with an analytic proof is a waste of time, but such a proof will be hard to say the least.

Sean

On Sun, Mar 14, 2021 at 01:14 PM, David Kirkby wrote:
On Sun, 14 Mar 2021 at 01:47, Reginald Beardsley via <pulaskite=[email protected]> wrote:

If anyone knows of a rigorous proof that the Yagi-Uda is the "sharpest beam" I am *very* interested in reading it.? On inspection it seems plausible, but mathematics at that level is rather a black art to mere applied math people like me.

Thanks and..

Have Fun!
Reg
?
I find it extremely unlikely that such proof exists. You would of course need to start by defining what is the "sharpest beam". The diffraction limit puts a limit on the first sidelobe and some Yagi-Uda antennas have the first sidelobe approximately that.
?
I find it worrying that the ARRL no longer sell Lawson's book on Yagi-Uda antennas. It was an ARRL publication.? It was the book that taught me enough to write my own program to analyze the antenna. It is a fairly different concept to NEC. You could argue it give you an analytical expression for the far-field, as the far-field pattern depends on the self impedance of elements and the mutual impedance between them. But the formula for mutual impedance in Lawson's book makes the assumption the elements have zero diameter and are a half-wave long.
?
The National Bureau of Standards (NBS)? made lots of careful measurements on Yagi-Uda antennas. Lawson shows that one of them must be wrong - probably just a typo.
?
Dave
Re: "Projector of the Sharpest Beam of Electric Waves"

 

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For Collin & Zucker.?

Lawson is between $20 and $90-something. from sone sketchy booksellers.

On Mar 14, 2021, at 16:46, Reginald Beardsley via <pulaskite@...> wrote:


Bookfinder was vol 1& 2 for $485

On Sunday, March 14, 2021, 03:29:29 PM CDT, Dave Daniel <kc0wjn@...> wrote:


bookfinder. com finds sone copies of Lawson. Somewhat expensive second-hand (but not $500!).

DaveD

On Mar 14, 2021, at 16:14, David Kirkby <drkirkby@...> wrote:

On Sun, 14 Mar 2021 at 01:47, Reginald Beardsley via <pulaskite=[email protected]> wrote:

If anyone knows of a rigorous proof that the Yagi-Uda is the "sharpest beam" I am *very* interested in reading it.? On inspection it seems plausible, but mathematics at that level is rather a black art to mere applied math people like me.

Thanks and..

Have Fun!
Reg

I find it extremely unlikely that such proof exists. You would of course need to start by defining what is the "sharpest beam". The diffraction limit puts a limit on the first sidelobe and some Yagi-Uda antennas have the first sidelobe approximately that.

I find it worrying that the ARRL no longer sell Lawson's book on Yagi-Uda antennas. It was an ARRL publication.? It was the book that taught me enough to write my own program to analyze the antenna. It is a fairly different concept to NEC. You could argue it give you an analytical expression for the far-field, as the far-field pattern depends on the self impedance of elements and the mutual impedance between them. But the formula for mutual impedance in Lawson's book makes the assumption the elements have zero diameter and are a half-wave long.

The National Bureau of Standards (NBS)? made lots of careful measurements on Yagi-Uda antennas. Lawson shows that one of them must be wrong - probably just a typo.

Dave

Re: "Projector of the Sharpest Beam of Electric Waves"

 


Bookfinder was vol 1& 2 for $485

On Sunday, March 14, 2021, 03:29:29 PM CDT, Dave Daniel <kc0wjn@...> wrote:


bookfinder. com finds sone copies of Lawson. Somewhat expensive second-hand (but not $500!).

DaveD

On Mar 14, 2021, at 16:14, David Kirkby <drkirkby@...> wrote:

On Sun, 14 Mar 2021 at 01:47, Reginald Beardsley via <pulaskite=[email protected]> wrote:

If anyone knows of a rigorous proof that the Yagi-Uda is the "sharpest beam" I am *very* interested in reading it.? On inspection it seems plausible, but mathematics at that level is rather a black art to mere applied math people like me.

Thanks and..

Have Fun!
Reg

I find it extremely unlikely that such proof exists. You would of course need to start by defining what is the "sharpest beam". The diffraction limit puts a limit on the first sidelobe and some Yagi-Uda antennas have the first sidelobe approximately that.

I find it worrying that the ARRL no longer sell Lawson's book on Yagi-Uda antennas. It was an ARRL publication.? It was the book that taught me enough to write my own program to analyze the antenna. It is a fairly different concept to NEC. You could argue it give you an analytical expression for the far-field, as the far-field pattern depends on the self impedance of elements and the mutual impedance between them. But the formula for mutual impedance in Lawson's book makes the assumption the elements have zero diameter and are a half-wave long.

The National Bureau of Standards (NBS)? made lots of careful measurements on Yagi-Uda antennas. Lawson shows that one of them must be wrong - probably just a typo.

Dave

Re: "Projector of the Sharpest Beam of Electric Waves"

 

On that note, another book by Collin ("Antennas and Radiowave Propagation) that isn't in my work office has this to say about parasitic arrays:
Parasitic arrays have usually been designed by experimental methods because of the difficulty of calculating the mutual impedances, the element lengths, and the optimum spaces, since these parameters are all interrelated in a complex nonlinear way.
I certainly don't think discussing the possibility of coming up with an analytic proof is a waste of time, but such a proof will be hard to say the least.

Sean

On Sun, Mar 14, 2021 at 01:14 PM, David Kirkby wrote:
On Sun, 14 Mar 2021 at 01:47, Reginald Beardsley via <pulaskite=[email protected]> wrote:

If anyone knows of a rigorous proof that the Yagi-Uda is the "sharpest beam" I am *very* interested in reading it.? On inspection it seems plausible, but mathematics at that level is rather a black art to mere applied math people like me.

Thanks and..

Have Fun!
Reg
?
I find it extremely unlikely that such proof exists. You would of course need to start by defining what is the "sharpest beam". The diffraction limit puts a limit on the first sidelobe and some Yagi-Uda antennas have the first sidelobe approximately that.
?
I find it worrying that the ARRL no longer sell Lawson's book on Yagi-Uda antennas. It was an ARRL publication.? It was the book that taught me enough to write my own program to analyze the antenna. It is a fairly different concept to NEC. You could argue it give you an analytical expression for the far-field, as the far-field pattern depends on the self impedance of elements and the mutual impedance between them. But the formula for mutual impedance in Lawson's book makes the assumption the elements have zero diameter and are a half-wave long.
?
The National Bureau of Standards (NBS)? made lots of careful measurements on Yagi-Uda antennas. Lawson shows that one of them must be wrong - probably just a typo.
?
Dave
Re: "Projector of the Sharpest Beam of Electric Waves"

 

开云体育

bookfinder. com finds sone copies of Lawson. Somewhat expensive second-hand (but not $500!).

DaveD

On Mar 14, 2021, at 16:14, David Kirkby <drkirkby@...> wrote:

On Sun, 14 Mar 2021 at 01:47, Reginald Beardsley via <pulaskite=[email protected]> wrote:

If anyone knows of a rigorous proof that the Yagi-Uda is the "sharpest beam" I am *very* interested in reading it.? On inspection it seems plausible, but mathematics at that level is rather a black art to mere applied math people like me.

Thanks and..

Have Fun!
Reg

I find it extremely unlikely that such proof exists. You would of course need to start by defining what is the "sharpest beam". The diffraction limit puts a limit on the first sidelobe and some Yagi-Uda antennas have the first sidelobe approximately that.

I find it worrying that the ARRL no longer sell Lawson's book on Yagi-Uda antennas. It was an ARRL publication.? It was the book that taught me enough to write my own program to analyze the antenna. It is a fairly different concept to NEC. You could argue it give you an analytical expression for the far-field, as the far-field pattern depends on the self impedance of elements and the mutual impedance between them. But the formula for mutual impedance in Lawson's book makes the assumption the elements have zero diameter and are a half-wave long.

The National Bureau of Standards (NBS)? made lots of careful measurements on Yagi-Uda antennas. Lawson shows that one of them must be wrong - probably just a typo.

Dave

Re: "Projector of the Sharpest Beam of Electric Waves"

 

On Sun, 14 Mar 2021 at 19:47, Dr. David Kirkby <drkirkby@...> wrote:

Although good for numerical work, I believe Mathematica is king when it comes to symbolic maths. There's a home version of that, but it is more than twice the price of MATLAB.
?
I mean MATLAB is good for numerical work - far more so than Mathematica. But for symbolic maths, Mathematica wins hands down, and you can get that for the cost of a Raspberry Pi, but the performance is limited by that of the Raspberry Pi.

Dave


Re: "Projector of the Sharpest Beam of Electric Waves"

 

On Sun, 14 Mar 2021 at 01:47, Reginald Beardsley via <pulaskite=[email protected]> wrote:

If anyone knows of a rigorous proof that the Yagi-Uda is the "sharpest beam" I am *very* interested in reading it.? On inspection it seems plausible, but mathematics at that level is rather a black art to mere applied math people like me.

Thanks and..

Have Fun!
Reg

I find it extremely unlikely that such proof exists. You would of course need to start by defining what is the "sharpest beam". The diffraction limit puts a limit on the first sidelobe and some Yagi-Uda antennas have the first sidelobe approximately that.

I find it worrying that the ARRL no longer sell Lawson's book on Yagi-Uda antennas. It was an ARRL publication.? It was the book that taught me enough to write my own program to analyze the antenna. It is a fairly different concept to NEC. You could argue it give you an analytical expression for the far-field, as the far-field pattern depends on the self impedance of elements and the mutual impedance between them. But the formula for mutual impedance in Lawson's book makes the assumption the elements have zero diameter and are a half-wave long.

The National Bureau of Standards (NBS)? made lots of careful measurements on Yagi-Uda antennas. Lawson shows that one of them must be wrong - probably just a typo.

Dave

Re: "Projector of the Sharpest Beam of Electric Waves"

 

Might be worth trying on a Pi 4. It is _much_ more powerful than any previous Pi.

Sean


On Sun, Mar 14, 2021 at 12:47 PM, David Kirkby wrote:
However, if you have a lot of patience, then you can use Mathematica for free on a Raspberry Pi. I tried it on an earlier Pi (not sure what version), but not a very early version of the Pi. I found Mathematica to be painfully slow.
Re: "Projector of the Sharpest Beam of Electric Waves"

 

Out of print books, ugh. Reminds me of a class I took where the instructor wanted to use Christopher Van Wyk's excellent "Data Structures and C Programming" which is out of print. Van Wyk was enthusiastic about getting it redone for use, but the publisher nixed that. Wouldn't even allow it to be scanned for the class.

Perhaps if enough people are interested they might reissue "Antenna Theory", but these are very niche books whose audience is probably the kind of people who have them already. :o)


On Sun, Mar 14, 2021 at 12:17 PM, Reginald Beardsley wrote:
Ouch!!!!! $500 and up used!
Re: "Projector of the Sharpest Beam of Electric Waves"

 


Dr David Kirkby Ph.D C.Eng MIET
Email: drkirkby@... Web:
Kirkby Microwave Ltd (Tel 01621-680100 / +44 1621-680100)
Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT.





On Sun, 14 Mar 2021 at 14:50, Dave Daniel <kc0wjn@...> wrote:

For some time I have wanted to start using Gnu Octave. The last time I looked, the authors of that code considered any differences between MatLab and Octave to be a bug in Octave. It appears that Octave now has a wide variety of packages which support various computational methods, similar to MatLab's Toolboxes. I did not see an Octave package for PDEs, though.

At one time the MathWorks would sell one a copy of MatLab, Simulink and whatever toolboxes one wished to purchase for a fraction of the commercial cost if one signed an agreement that precluded the commercial use of that copy of MatLab. I did this in 2000; when I went to re-up, The MathWorks informed me that they no longer supported that option. Later on, I believe they expanded the capabilities of the student version of MatLab. I briefly pursued the use of that but did not explore it in depth.


MATLAB is very economical for home use


Although good for numerical work, I believe Mathematica is king when it comes to symbolic maths. There's a home version of that, but it is more than twice the price of MATLAB.

However, if you have a lot of patience, then you can use Mathematica for free on a Raspberry Pi. I tried it on an earlier Pi (not sure what version), but not a very early version of the Pi. I found Mathematica to be painfully slow.

DaveD
Re: "Projector of the Sharpest Beam of Electric Waves"

 

On Sun, 14 Mar 2021 at 04:21, Dave Daniel <kc0wjn@...> wrote:
There are also apparently? MatLab and FORTRAN programs on the CD that
was included in the book. Unfortunately, I no longer have access to
FORTRAN compilers or MatLab.

gcc is a free compiler, that compiles Fortran, as well as numerous other languages.?

Octave is a free clone of MATLAB, but it does not have the extensive range of toolboxes support that MATLAB has, so if the code depended on a toolbox, you might be out of luck. I think there's a pretty inexpensive home version of MATLAB.

DaveD
Re: "Projector of the Sharpest Beam of Electric Waves"

 

开云体育

I see one copy available. $485. Wow. ?

I bought my set used in the early 80s when I was collecting all of Collin’s work. I think I paid around $100 for the set.

DaveD

On Mar 14, 2021, at 15:17, Reginald Beardsley via <pulaskite@...> wrote:

Ouch!!!!! $500 and up used!


On Sunday, March 14, 2021, 02:10:37 PM CDT, Sean Turner <[email protected]> wrote:


Indeed...I couldn't think of the co-author's name to save my life either!

Sean

On Sun, Mar 14, 2021 at 12:06 PM, Dave Daniel wrote:
re you referring to the two-volume set by Collin a d Zucker?
?
Thanks.
?
DaveD
?
Re: "Projector of the Sharpest Beam of Electric Waves"

 

开云体育

Thank you, Sean.

Yes, that is a very good set of texts about antennas. I haven’t looked in a while, but I believe it is now completely unavailable. Krieger or someone (is Dover still around?) should see if they can get the rights to re-publish it.

DaveD

On Mar 14, 2021, at 15:10, Sean Turner <[email protected]> wrote:

Indeed...I couldn't think of the co-author's name to save my life either!

Sean

On Sun, Mar 14, 2021 at 12:06 PM, Dave Daniel wrote:
re you referring to the two-volume set by Collin a d Zucker?
?
Thanks.
?
DaveD
?
Re: "Projector of the Sharpest Beam of Electric Waves"

 

Ouch!!!!! $500 and up used!


On Sunday, March 14, 2021, 02:10:37 PM CDT, Sean Turner <[email protected]> wrote:


Indeed...I couldn't think of the co-author's name to save my life either!

Sean


On Sun, Mar 14, 2021 at 12:06 PM, Dave Daniel wrote:
re you referring to the two-volume set by Collin a d Zucker?
?
Thanks.
?
DaveD
?
Re: "Projector of the Sharpest Beam of Electric Waves"

 

Indeed...I couldn't think of the co-author's name to save my life either!

Sean


On Sun, Mar 14, 2021 at 12:06 PM, Dave Daniel wrote:
re you referring to the two-volume set by Collin a d Zucker?
?
Thanks.
?
DaveD
?
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