QuoteThe smaller antennaAre you referring to the antenna with circumference of 1 wavelength?
The smaller antenna
An artefact of my implementation is that as the loop gets smaller the number of point sources making up the loop are reduced. It is still one point for every meep time step but it takes a lot fewer time steps to walk around the smaller loop. I don't know if that will have an adverse effect or not. It does affect the amplitude of the signal.
Quote from: aero on 09/04/2015 09:01 pmAn artefact of my implementation is that as the loop gets smaller the number of point sources making up the loop are reduced. It is still one point for every meep time step but it takes a lot fewer time steps to walk around the smaller loop. I don't know if that will have an adverse effect or not. It does affect the amplitude of the signal.Yes smaller loops gives lower amplitudes(also true in the real world, lower coupling...), but the wrong pattern at the loop could lead to a wrong field pattern means wrong mode..On the other hand (for most geometries of such a resonator) there is only one mode possible, theoretically.I don't believe that this is an artefact, half the number of points means you will see only one color for each half cycle. (Is that right??)How it looks like for a lambda/4 circumference of the loop? Can you upload one or two full cycles? Myself or someone else will make a gif based on it
I've been making resonance runs for this antenna with the circumferences mentioned and see two interesting differences in the numbers from the dipole antennas used previously.First though, the resonant frequency seems to be the same 2.50 GHz calculated before. More exactly, this 2.50021516E+009, 2.49990486E+009,2.49989601E+009 for three runs.1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?2 ) And this is interesting. When the drive frequency is less than the resonance frequency, Q does not suffer very much (20%) but the imaginary part of the complex amplitude is huge compared to the real part. This characteristic goes away when driving the cavity at the Harminv calculated resonant frequency. I don't recall what this means but I think I recall that the large imaginary component was related to something important. Dispersion, maybe?Anyway, I can organize and post those numbers if there is interest.
...1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...
Quote from: aero on 09/04/2015 10:48 pm...1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?
Quote from: Rodal on 09/05/2015 12:44 amQuote from: aero on 09/04/2015 10:48 pm...1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?I used each of them but only one at a time. A single component exciting the cavity for each of 6 runs. All 6 Q values were higher than the Q I'm getting with the loop. One by only a small factor (1.5) and the rest by orders of magnitude. It may be that I am not detecting the right mode, using Hx and keep forgetting to change it. Hx is a TM mode component. But without your question, that possibility wouldn't have occurred to me for days. I'll check now.Regarding the huge Imaginary component, I'm talking about amplitude, not frequency. I agree, for frequency that couldn't happen.
Quote from: aero on 09/05/2015 02:02 amQuote from: Rodal on 09/05/2015 12:44 amQuote from: aero on 09/04/2015 10:48 pm...1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?I used each of them but only one at a time. A single component exciting the cavity for each of 6 runs. All 6 Q values were higher than the Q I'm getting with the loop. One by only a small factor (1.5) and the rest by orders of magnitude. It may be that I am not detecting the right mode, using Hx and keep forgetting to change it. Hx is a TM mode component. But without your question, that possibility wouldn't have occurred to me for days. I'll check now.Regarding the huge Imaginary component, I'm talking about amplitude, not frequency. I agree, for frequency that couldn't happen.So, if you used only one component before, why use 3 components now?I can see using 2 components for a circle instead of 1 component for a straight dipole aligned along one of the Cartesian axes. To define a component at an angle to the Cartesian axes you need the 2 components in the plane of the circle, but I have no idea as to why you are using a 3rd component, which is perpendicular to that plane.
Quote from: Rodal on 09/05/2015 02:13 amQuote from: aero on 09/05/2015 02:02 amQuote from: Rodal on 09/05/2015 12:44 amQuote from: aero on 09/04/2015 10:48 pm...1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?I used each of them but only one at a time. A single component exciting the cavity for each of 6 runs. All 6 Q values were higher than the Q I'm getting with the loop. One by only a small factor (1.5) and the rest by orders of magnitude. It may be that I am not detecting the right mode, using Hx and keep forgetting to change it. Hx is a TM mode component. But without your question, that possibility wouldn't have occurred to me for days. I'll check now.Regarding the huge Imaginary component, I'm talking about amplitude, not frequency. I agree, for frequency that couldn't happen.So, if you used only one component before, why use 3 components now?I can see using 2 components for a circle instead of 1 component for a straight dipole aligned along one of the Cartesian axes. To define a component at an angle to the Cartesian axes you need the 2 components in the plane of the circle, but I have no idea as to why you are using a 3rd component, which is perpendicular to that plane.Well, no better idea, and anyway that was left over from debugging. Both TE and TM have 3 components, that's why the capability is built in. I have done as you suggested and am now making a run with only Ex and Ey excitation. Those two components are in the TE mode which is what I am hoping to excite. I did change the Harminv detection location and component to Ey located 1/4 wavelength from the small end and maybe 70% toward the wall from the zero axis. It has been very near the center of the cavity. (Where is the best place to locate the detector?) This change increased the calculated Q to 7800 which is up from 3722. That is of course another indication of the futility of trying to adjust the copper model to get realistic calculated Q values. The calculated Q depends on several seemingly extraneous parameters not related to the material model. Ok - run finished - exciting with only Ex and Ey reduced Q to 6661 and reduced the detected resonant frequency by 10 kHz. And in case I didn't mention it, this is with a 1/4 wave length circumference loop, 1/4 wavelength from the big end and centered.
The text by Woodward you refer to was cowritten with Paul March:Woodward, James F.; Mahood, Thomas L.; March, Paul (July 2001). "Rapid Spacetime Transport and Machian Mass Fluctuations: Theory and Experiment". JPC 2001 Proceedings. 37th AIAA/ASME Joint Propulsion Conference, Salt Lake City, Utah. American Institute of Aeronautics and Astronautics. doi:10.2514/6.2001-3907Most importantly, it was written in 2001, while Puthof's Polarizable Vacuum theory was only a few months old. Nowadays Woodward does not think PV is realistic anymore, nor any ZPF theory (including McCulloch's MiHsC or White's QVF conjecture) to explain Mach effects. He is very clear about that when asked on that matter. Woodward is even currently writing a paper demonstrating why virtual particles of the vacuum can not be used for propulsion.
Question: "What do you think of the EMdrive work?"March's answer: The proposed E&M/SRT conjecture IMO is garbage. The experimental results is tantalizing, but it has to be repeated in a vacuum chamber to get rid of possible spurious error sources for the thrust signatures observed. If it still moves in a 1x10-4 Torr vacuum, then we have to explain what is going on in view of Jim's work.
New meep simulations source link, below.I've shared my folder meeper-files, which is laid out as follows:meeper-files/ CE2-0009-150904/ - all files associated with this run in this folder cvs-directory/ - the cvs files from the Continuous run 400+ files CE2-8Ey-dual_dipoles-250-csv.log - log file from running CE2-csv.sh CE2-dual_dipoles-250res.ctl - control file for the Continuous run at 250 resolution CE2-dual_dipoles-C-250res.log - log file from Continuous run CE2-dual_dipoles-G.ctl - control file for the Gaussian run at 100 resolution CE2-dual_dipoles-G.log - log file from Gaussian run meep-data-description-CE-2r9-32cy.txt - my take at the data description file scripts/ CE2-csv.sh - my current version of the parameterized script fileNote that in the future, there will be better agreement between run names (CE2r9), directory names (CE2-0009-150904), control file names (CE2-dual_dipoles-xxx), and log file names. Sorry about that - it's been an evolution. I can recreate the files with the CE2-0009 common prefix, if you'd like.Link to meeper-files folder is https://drive.google.com/folderview?id=0B527OOY4hxdZfldTN2FoVm5SRDZ2MHFJYmhaM2ZFcXVEeklpd3NnTy1RUUtnS3d1YllCWGc&usp=sharingFolder is shared public for viewing only. Hope you'll find them useful.Edit - correct root folder name to meeper-files.