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#1180 by Rodal on 13 Apr, 2016 13:34
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What is your opinion of Trunov's paper on the EM Drive, also involving general relativity ?
I have absolutely no russian language skills.
See attachment (I enclose the English language version. There is also an original Russian version if you find that language easier to read)
GENERAL RELATIVITY AND DYNAMICAL MODEL OF ELECTROMAGNETIC DRIVE
Трунев Александр Петровичк.ф.-м.н., Ph.D., директор
Alexander Trunev
Cand.Phys.-Math.Sci., Ph.D., C.E.O.
Научный журнал КубГАУ, №116(02), 2016 года
I noticed at glance that the claim is mass-reducing - my claim is space-reducing and hence the increace of apparent non-inertial mass.
Maybe this difference is due to my understanding that space fragments are streaming to masses, there are no pulling force signals from gravitating body. The gradient of space tension of vacuum quanta affect accelerations.
Another paper using gravitation relativity (this time using a scalar-tensor theory) to justify the claims of anomalous force for the EM Drive is the one by Minotti, published in the more prestigious peer-reviewed journal Grav. & Cosmol:
Scalar-tensor theories and asymmetric resonant cavities
Fernando O. Minotti
Grav. & Cosmol. 19 (2013) 201
DOI: 10.1134/S0202289313030080
http://arxiv.org/abs/1302.5690
The problem with the theory is that it leads to gravitational effect due to magnetism that are dissonant with measurements around the Earth's magnetic field. Minotti proposes that a nonlinear theory may address this discrepancy. Minotti does an excellent job (compared to other authors) of discussing the exact solution for the electromagnetic fields in the truncated cone cavity.
Please let us know what you think of this paper vis-a-vis your theory.
...
Another paper using General Relativity to study the EM Drive I would like to bring to your attention is:
Einstein-Maxwell equations for asymmetric resonant cavities
Marco Frasca
http://arxiv.org/abs/1505.06917v1
1) The paper uses standard General Relativity by Einstein.
2) Dr. Frasca shows that the effect due to General Relativity is extremely small (by several orders of magnitude) to explain the anomalous thrust claimed by several EM Drive researchers. The effect of General Relativity to produce an anomalous force is so small that it is orders of magnitude smaller than the thrust of a photon rocket.
3) Dr. Frasca shows that the effect due to General Relativity is related to the geometric singularity at the apex of the cone: the General Relativity effect becomes larger the closer the truncated cone is to a cone: the closer the geometry is to the apex of the cone, and the smaller is the cone angle. The effect due to General Relativity becomes smaller for truncated cone geometries closer to a cylinder with constant cross section.
4) Your proposed geometry as per this message:The rendered image of an optimized cavity for gravity guiding standing waves.
Can you provide the exact dimensions, including the radius for the spherical end-plates? Also, what frequency? I've done a sweep on a frustum with spherical end-plates, but not one as "wide" as yours. May be interesting to see.
These are inner dimensions of the cavity. It's filled up with inert air, calculatory speed of light: 299 700 km/s,
The frequency could be multiple of 484,9514563 MHz i.e. 2,424757282 GHz or 4,849514563 GHz TE-mode.
differs substantially from the ideal geometry according to Dr. Frasca, using General Relativity, because your proposed geometry stops the truncated cone well short of reaching the apex of the cone.
5) Your comments regarding the disagreement between your (unpublished) theory using General Relativity and Dr. Frasca's published analysis using General Relativity would be appreciated. -
#1181 by Monomorphic on 13 Apr, 2016 13:45
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These are inner dimensions of the cavity. It's filled up with inert air, calculatory speed of light: 299 700 km/s,
The frequency could be multiple of 484,9514563 MHz i.e. 2,424757282 GHz or 4,849514563 GHz TE-mode.
I believe those dimensions are much larger than any emdrive built to date. See comparison below between my frustum dimensions. Also ran a sim using the 2.424757282Ghz. Being quite large, this model has over 650 triangles. So I can only do a one or two of these, and couldn't realistically do a frequency sweep unless I let it run for many hours.
I also noticed something odd about your geometry. It's not a perfect concave convex cavity like others I have modeled. Your big end radius is a little larger than it should be. This is not a comment on theory, just geometry.
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#1182 by Rodal on 13 Apr, 2016 13:54
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These are inner dimensions of the cavity. It's filled up with inert air, calculatory speed of light: 299 700 km/s,
The frequency could be multiple of 484,9514563 MHz i.e. 2,424757282 GHz or 4,849514563 GHz TE-mode.
I believe those dimensions are much larger than any emdrive built to date. See comparison below between my frustum dimensions. Also ran a sim using the 2.424757282Ghz. Being quite large, this model has over 650 triangles. So I can only do a one or two of these, and couldn't realistically do a frequency sweep unless I let it run for many hours.
I also noticed something odd about your geometry. It's not a perfect concave convex cavity like others I have modeled. Your big end radius is a little larger than it should be. This is not a comment on theory, just geometry.
Thank you for conducting the simulation.
The solution to Maxwell's equations does not look like the ray solution Eusa had posted previously.
This:
does not look like this:
This was a subject of discussion previously with TheTraveller: the fact that it is the electromagnetic field solution that matters and that the electromagnetic fields do not behave like photon ray solutions. (*)
One would need to use optical lasers to have a ray-solution behavior.
Monomorphic, you show the surface current solution on the faces, from which one can ascertain the multipolar magnetic field.
Perhaps you could also show images of the magnetic field distribution inside the cavity to appreciate more clearly its variation in the cavity as well. Thank you!
_______________
(*) The solution to Maxwell's equations of such a closed cavity do not look like what Shawyer has proposed:
there is electromagnetic pressure from the electromagnetic fields on the side walls of the cavity. The reflection of the electromagnetic fields and the electromagnetic pressure from the side walls cannot be ignored.
The solution is not a ray solution: one cannot visualize it as being due to a ray solution. The solution is not one of photons traveling in straight rays, and it is not one of spherical waves traveling in free-space. The side-walls matter.
Getting rid of the side walls (as it was proposed by TheTraveller) would destroy the closed cavity solution, severely decrease the quality of resonance Q, and be unsafe (unless shielded by other means that would further introduce further field effects from such shielding). -
#1183 by Monomorphic on 13 Apr, 2016 14:07
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Perhaps you could also show images of the magnetic field distribution inside the cavity to appreciate more clearly its variation in the cavity as well. Thank you!
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#1184 by Rodal on 13 Apr, 2016 14:20
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Double checking the dimensions:These are inner dimensions of the cavity. It's filled up with inert air, calculatory speed of light: 299 700 km/s,
The frequency could be multiple of 484,9514563 MHz i.e. 2,424757282 GHz or 4,849514563 GHz TE-mode.
I believe those dimensions are much larger than any emdrive built to date. See comparison below between my frustum dimensions. ..
Eusa's dimensions are in millimeters.Eusa, are your dimensions in mm, cm? Thank you for your input. I did not do calculations based on speed to guess as I am unsure of a proper equation.
My dimensions are in mm.
So Eusa's length is 24 inches (2 feet)
618 mm = 24.331 inches = (2.028 feet) compared to NASA's 228.6 mm it is 2.703 times longer than NASA
(your drawing comparison looks OK)
996 mm = 39.213 inches = (3.268 feet) compared to NASA's 279.4 mm it is 3.565 times bigger than NASA
(your drawing comparison looks OK)
443 mm = 17.441 inches = (1.453 feet) compared to NASA's 158.75 mm it is 2.791 times bigger than NASA
(your drawing comparison looks OK)
Such a larger geometry (about 3 times larger dimensions, hence volume about 27 times larger) should resonate in the same mode shape at a lower frequency. Hence using (similar frequency as in Yang or in Shawyer Demonstrator) 2.42 Ghz results in the excitation of a significantly higher mode shape than the ones excited by NASA, Shawyer or Yang.
If excited at the corresponding scaled lower frequency, this geometry should result in a higher Q than the Q's in smaller geometries used in EM Drive experiments up to now.
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#1185 by Eusa on 13 Apr, 2016 18:07
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I have busy moments at work nowadays, but I read all your great postings.
Briefly: in Marco Frasca's paper I see some encouraging features, for example the effect out of math itself which could be multiply via Planck scaling with climbing incoherent radiation, I think. I'll study the text thorough more accurately, maybe there are no actual contradictions in relation to my findings. The dielectric effect is obvious too but have optical challenges when trying realize... -
#1186 by Eusa on 13 Apr, 2016 18:18
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Is it possible set the second radiator cavity behind smaller perforated reflector? As in my original drawing...These are inner dimensions of the cavity. It's filled up with inert air, calculatory speed of light: 299 700 km/s,
The frequency could be multiple of 484,9514563 MHz i.e. 2,424757282 GHz or 4,849514563 GHz TE-mode.
I believe those dimensions are much larger than any emdrive built to date. See comparison below between my frustum dimensions. Also ran a sim using the 2.424757282Ghz. Being quite large, this model has over 650 triangles. So I can only do a one or two of these, and couldn't realistically do a frequency sweep unless I let it run for many hours.
I also noticed something odd about your geometry. It's not a perfect concave convex cavity like others I have modeled. Your big end radius is a little larger than it should be. This is not a comment on theory, just geometry.
What would a simulation reveal?
The next thing is side walls fresnel effect optical layering and so on... But let's take one step at a time. -
#1187 by X_RaY on 13 Apr, 2016 18:31
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X_Ray, you also highlighted the two different modes: TE012 and TM212 ---I did know this but it was argued in several pages back (of this thread) that TM212 was contraindicated. Yes, as you can see in EM drive experimental results TM212 was noted in different frequencies. FL
Till now no one knows exactly which mode would produce the highest thrust*. Of course there are strong tendencies to high Q modes, especially TE modes. The best mode order (TXmnp) is unclear.
I would focus on modes like TE023 or something like this. The reason is there are lobes in such a pattern who are not in contact to the lossy surface of the cavity, therefore there is a realistic chance that the Q also increases. This should be tested. IMHO
There are several ways to archiv such mode: higher frequency, bigger cavity, larger dielectric constant within the cavity( cheramic or polymer filling) this last option also increases the loss because of the ε“.
*provided that the "thrust" is not based on Lorentz force, thermal effects or other known physics. Still waiting for SeeShells, Monomorphic, Rfmwguy, other DIY and the next NASA report
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#1188 by Rodal on 13 Apr, 2016 19:27
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I have busy moments at work nowadays, but I read all your great postings.
NSF member "StrongGR" has signed his posts as Dr. Marco Frasca and has discussed his paper "Einstein-Maxwell equations for asymmetric resonant cavities" with NSF members in previous EM Drive threads.
Briefly: in Marco Frasca's paper I see some encouraging features, for example the effect out of math itself which could be multiply via Planck scaling with climbing incoherent radiation, I think. I'll study the text thorough more accurately, maybe there are no actual contradictions in relation to my findings. The dielectric effect is obvious too but have optical challenges when trying realize...
See his great posts here:
http://forum.nasaspaceflight.com/index.php?action=profile;area=showposts;u=47907 -
#1189 by Rodal on 13 Apr, 2016 19:55
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Mr. Mike McCulloch new paper "Testing quantised inertia on the emdrive"
http://arxiv.org/abs/1604.03449
Apologies if it was already posted.
Thank you for posting McCulloch's new paper that I don't recall being posted here before.
Dr. McCulloch should be applauded for making a very testable prediction to elucidate the veracity of his hypothesis:Quote from: Dr. Mike McCullochAs a direct test MiHsC predicts that the thrust can be reversed by making the length L equal to the width of the narrow end.
This is what science is about: making quantitative predictions that can be quantitatively nullified or verified by experiments.
I hope that the Do-It-Yourself community in this EM Drive threads rises to this challenge to ascertain whether indeed when the length L becomes equal to the small end, whether the thrust force is reversed in direction.
Also Dr. McCulloch has recently tried to tackle the energy-conservation paradox (looking forward to comments from Prof. Frobnicat
here ) using information theory (*)
http://physicsfromtheedge.blogspot.com/2016/04/informational-mihsc.htmlQuote from: Dr. Mike McCullochif you assume that it is not mass-energy that is conserved, but Energy plus Mass plus horizon-Information (EMI) then you get MiHsC. In the diagram below, when a shapeship accelerates, then the Rindler horizon it sees comes closer and shrinks. This deletes information stored on the horizon, which appears as inertia in the MiHsC framework:
(Bold color added for emphasis)
To those wondering where all the energy needed for the new effects predicted by MiHsC comes from, my original way of explaining it (which is still valid) is to say that information horizons create gradients in the usually uniform zero point field / Unruh radiation from which new energy can be extracted. The second (equally valid) way of explaining it is: mass-energy appears from the destruction of horizon-information. Understanding leads to control, and this is a new potential energy source
I like the fact that Dr. Mike McCulloch tries to tackle the energy paradox raised by the EM Drive, rather than try to escape from it, something that I have not seen Mr. Shawyer or Prof. Yang do. Dr. McCulloch admits that if the EM Drive works as claimed by experimenters, it should be a new potential energy source (perhaps an energy source to feed into another EM Drive for propulsion purposes).
________
(*) Information theory was invented by the great MIT Professor Claude Shannon in his outstanding 1948 paper "A Mathematical Theory of Communication". I use Information Theory daily in my work, so I personally look forward to reading Dr. McCulloch's paper when it becomes available.
Professor Shannon, a distant relative of Thomas Edison, besides being a Prof. at MIT, was also affiliated with Bell Laboratories from 1941 to 1972. Shannon received his PhD in mathematics from MIT in 1940. To satisfy the MIT language requirement, he had to hire tutors and worked repeatedly with stacks of flash cards. He had to take the German exam twice. During World War II, Dr. Shannon, a noted scamgrapher, worked on secrecy systems at Bell Labs. His team's work on anti-aircraft directors--devices that observe enemy planes or missiles and calculate the aim of counter missiles--became crucial when German rockets were used in the blitz of England. Professor Shannon had a whimsical side and developed a juggling machine, rocket-powered Frisbees, motorized Pogo sticks, a mind-reading machine, a mechanical mouse that could navigate a maze and a device that could solve the Rubik's Cube puzzle. At Bell, he was remembered for riding the halls on a unicycle while simultaneously juggling three balls .
Prof. Shannon passed away in 2001 after a long battle with Alzheimer's disease. He was 84 years old.
Also Dr. Notsosureofit has been looking at the entropy problem for the EM Drive concerning his Notsosureofit hypothesis. -
#1190 by FattyLumpkin on 13 Apr, 2016 20:25
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X_Ray, were you satisfied with the information I gave to you yesterday...re dimension and calculated frequency et al.?---Are you satisfied with the sim that you performed? Once again, sorry for the confusion re the figures.
thank you for your help FL -
#1191 by X_RaY on 13 Apr, 2016 20:44
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X_Ray, were you satisfied with the information I gave to you yesterday...re dimension and calculated frequency et al.?---Are you satisfied with the sim that you performed? Once again, sorry for the confusion re the figures.
thank you for your help FL
Something seems wrong with you scaling because field calculations as well as numerical solutions predict a resonant frequency of about 6.1GHz instead of the suggested 5.2538GHz.
Please check the numbers I used in the related post, if you find a bug please let me know:
https://forum.nasaspaceflight.com/index.php?topic=39772.msg1516895#msg1516895
158.8mm / 2.794 = 56.8360773085mm = 5.68360773085cm
279.7mm / 2.794 = 100.107372942mm = 10.0107372942cm
228.6mm / 2.794 = 81.8181818182mm = 8.18181818182cm
2.1794GHz * 2.794 = 6.0892436GHz
Due to the coarse mesh (currently I use FEKO LIGHT) of the calculation the 6.12GHz seems close but not perfect, while increasing the number of points in my numerical solution the resonant frequency decreases slightly.
For 30 datopoints along the z axis instead of 15 of yesterdays calculation the resulting frequency is 6.082521515122712GHz, note that this is ~1/30 wavelength (for TE012) inside the cavity.
(1/3000 wavelength leads to 6.045465414581838GHz! not 5.2538GHz)
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#1192 by MazonDel on 13 Apr, 2016 20:59
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Not certain if this link was already seen before: http://www.digitaltrends.com/cool-tech/emdrive-news-rumors/?utm_source=o1&utm_medium=cpc&utm_campaign=highppv&umm_term=794533
Somewhat old, updated in Nov, but it seemed a relatively decent compilation of assorted bits of info on the drive. -
#1193 by Monomorphic on 13 Apr, 2016 22:02
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I hope that the Do-It-Yourself community in this EM Drive threads rises to this challenge to ascertain whether indeed when the length L becomes equal to the small end, whether the thrust force is reversed in direction.
This is an example of a frustum with L = small end diameter. Looks like many of the same modes are present. I would need to shift the dims so that a mode is excited at 2.45Ghz.
Does McCulloch's theory indicate if there is a length to end-plate diameter ratio that is best for regular (not reverse) thrust?
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#1194 by FattyLumpkin on 13 Apr, 2016 22:19
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HI X_Ray, thank you for you work, while I'm sure that the down scaled geometry is correct whether multiplying the original NASA dimension by .35791 or dividing by 2.794, the only remaining question I believe is frequency:
the frequency of 1.8804 for the original size frustum was selected because it produced the best result.
Irrespective of which way method is used: division or multiplication one comes up with only two number for an upscale frequency: 5.2538 GHz or 6.7301 GHz. However Dr. Rodal (as I recall) and others have stated that an up-scaled frequency by the numbers would most likely not be the frequency that would produce the best resonance. (My reference re Dr. Rodal here is based on my recollection, so Dr. please chime in here if I've got it wrong)! Indeed, several pages back I believe Monomorphic found resonance at 2.4 Gigs.
These dimensions of this downsized frustum are vital, because NASA might delay testing in micro-gravity, and said well resonating and thrust tested frustum will fit into a Cubesat and may thereby make for a real demonstration of the "EM effect". Please let me (us) know what your find. And, yes as aforementioned TE012 and TM212 modes are noted the NASA data, however TE012 was noted at 1.8804 GHz. FL -
#1195 by Rodal on 13 Apr, 2016 22:21
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I hope that the Do-It-Yourself community in this EM Drive threads rises to this challenge to ascertain whether indeed when the length L becomes equal to the small end, whether the thrust force is reversed in direction.
This is an example of a frustum with L = small end diameter. Looks like many of the same modes are present. I would need to shift the dims so that a mode is excited at 2.45Ghz.
Does McCulloch's theory indicate if there is a length to end-plate diameter ratio that is best for regular (not reverse) thrust?
Recall that other theories predict a reversal of the direction of the force, for example Minotti's theory based on gravitation coupling with electromagnetism, predicts that the force will change direction based on the mode shape.
Also Dr. White's QV theory makes that prediction based on the particular mode shape.
Since McCulloch's theory does not take into account the mode shapes (unlike Notsosureofit's hypothesis which does take the mode shape into account), I don't follow McCulloch's rationale for his hypothesis.
But it is something that somebody could run an experiment to verify or nullify. -
#1196 by Rodal on 13 Apr, 2016 22:25
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HI X_Ray, thank you for you work, while I'm sure that the down scaled geometry is correct whether multiplying the original NASA dimension by .35791 or dividing by 2.794, the only remaining question I believe is frequency:
the frequency of 1.8804 for the original size frustum was selected because it produced the best result.
Irrespective of which way method is used: division or multiplication one comes up with only two number for an upscale frequency: 5.2538 GHz or 6.7301 GHz. However Dr. Rodal (as I recall) and others have stated that an up-scaled frequency by the numbers would most likely not be the frequency that would produce the best resonance. (My reference re Dr. Rodal here is based on my recollection, so Dr. please chime in here if I've got it wrong)! ...
OK chiming in, per invitation
I don't recall stating that. I do recall making a point that the most important parameter for force/PowerInput according to all 3 theories: Shawyer, McCulloch and Notsosureofit is the quality of resonance Q, and I stated that everything else being the same, making the frustum smaller means a lower Q, hence lower force/PowerInput when making the frustum smaller according to all those 3 theories.
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#1197 by FattyLumpkin on 13 Apr, 2016 22:58
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Thanks Doc, I definitely remember about the reduced Q. Is it accurate to say that in a scaled down frustum that the scaled up frequency " by the exact % of the downscale" may not work as the best resonant frequency for the downscaled frustum. E.g. frustum X resonates best at 2.45 GHZ downsize frustum X by a factor of ten and upscale the frequency to 24.5GHz. Said downsized frustum does not necessarily resonate best at the "by the numbers" at the x 10 up-scaled frequency.
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#1198 by Rodal on 13 Apr, 2016 23:04
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Thanks Doc, I definitely remember about the reduced Q. Is it accurate to say that in a scaled down frustum that the scaled up frequency " by the exact % of the downscale" may not work as the best resonant frequency for the downscaled frustum. E.g. frustum X resonates best at 2.45 GHZ downsize frustum X by a factor of ten and upscale the frequency to 24.5GHz. Said downsized frustum does not necessarily resonate best at the "by the numbers" at the x 10 up-scaled frequency.
As shown here: https://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347 under the section "natural frequency scaling", and as per X-Ray, the natural frequency scales with a constant factor with dimensions. This is true for a homogenous cavity, without dielectric inserts asymmetrically placed in the cavity
The problem in your scaling is:
1) The frequency you were asking X-Ray to run was the one (1.8804 GHz TE012) that NASA run with a dielectric insert
2) If I am correct, X-Ray may be running his simulations without a dielectric insert.
The dielectric insert lowers the natural frequency of the cavity.
3) NASA's natural frequency for TE012 without a dielectric insert was 2.168 GHz (see https://forum.nasaspaceflight.com/index.php?topic=39214.msg1469866#msg1469866 ) but NASA obtained NO signfificant ANOMALOUS FORCE measurement without a dielectric insert, even when increasing the PowerInput by a factor exceeding 10 times higher power -
#1199 by FattyLumpkin on 13 Apr, 2016 23:25
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Understood, am not exactly sure why, but there was some confusion to start with when X_Ray was being so kind as to help with sims. This is because I did not indicate "cm" on my schematic. Additionally, I'm not sure he was aware that I was downscaling the NASA frustum and had chosen 1.8804GHz TE012...(as indicted in results had the "best" out come: mN/kW of 21.3). Having reviewed this I hope X_Ray is up to running a few more sims to find the "best" frequency for this "Cubesat frustum" Ciao!
here ) using information theory (*)