Search found 1294 matches

by thorsten
Sat 18 May 2019, 10:27
Forum: News
Topic: openEMS.de is back up again
Replies: 12
Views: 3268

Re: openEMS.de is back up again

Well it works for me on every device I can try and every location I am.

What about
http://openems.de
or
http://openems.de/start/index.php?show=home

the forum obviously seems to work...
by thorsten
Wed 01 May 2019, 18:57
Forum: Usage
Topic: Energy decay is not presented, but results are good
Replies: 4
Views: 105

Re: Energy decay is not presented, but results are good

It can be anywhere on the line as long as it is not "behind" the excitation plane (switched positions) and not inside the PML.
by thorsten
Wed 01 May 2019, 13:31
Forum: Usage
Topic: Correct use of meshing functions and excitation
Replies: 16
Views: 375

Re: Correct use of meshing functions and excitation

One more note from my observations: To increase accuracy of your results you should sooner or later add some proper edge meshing. See here for more info's: http://openems.de/index.php/FDTD_Mesh.html#FDTD_Mesh_example Namely the one-third/two-third rule for your flat metal parts (red lines in picture...
by thorsten
Wed 01 May 2019, 13:15
Forum: Usage
Topic: Correct use of meshing functions and excitation
Replies: 16
Views: 375

Re: Correct use of meshing functions and excitation

The problem with the antenna is, that it has to be matched to the IC some more. Means I need to be able to simulate it with a complex port impedance. Solving the matching problem should not be done in a full-wave solver. Use Qucs for that, e.g. by exporting s11 as touchstone and importing it in Quc...
by thorsten
Wed 01 May 2019, 13:13
Forum: Usage
Topic: Correct use of meshing functions and excitation
Replies: 16
Views: 375

Re: Correct use of meshing functions and excitation

Does the AddlumpedPort add a series or a parallel resistance ? In series or parallel to what? The lumped R is in between the feed arms if that is what you want to know... Also is it possible to create a complex port impedance or would that only be achievable with adding a lumped capacitor to the po...
by thorsten
Wed 01 May 2019, 09:11
Forum: Usage
Topic: Correct use of meshing functions and excitation
Replies: 16
Views: 375

Re: Correct use of meshing functions and excitation

Well the mesh looks good now. What I found odd is the extremely high impedance at resonance. I changed the feed_R to 4000 too to match it and get more energy into the resonance. Furthermore I added an electric field dump at 1.58GHz to see what the resonance looks like. res.png That really does not l...
by thorsten
Mon 29 Apr 2019, 19:50
Forum: Usage
Topic: Correct use of meshing functions and excitation
Replies: 16
Views: 375

Re: Correct use of meshing functions and excitation

Well what I do not like on the initial look at it, is that your metal fingers and the gab in between only are one cell thick. I don't think that this is a good idea in general and especially considering the port is pinched between the two metal strips and only over one cell... Make this at least 3 c...
by thorsten
Tue 23 Apr 2019, 21:43
Forum: Usage
Topic: Correct use of meshing functions and excitation
Replies: 16
Views: 375

Re: Correct use of meshing functions and excitation

smoothmeshlines(meshline.x, resolution, 1); --> doesn't work somehow and octave is just loading and not continuing in the terminal. You just have to be careful what you put in and with what parameters. It can get stuck or in an endless loop for problematic setups... So would you recommend making th...
by thorsten
Tue 23 Apr 2019, 21:21
Forum: Usage
Topic: Energy decay is not presented, but results are good
Replies: 4
Views: 105

Re: Energy decay is not presented, but results are good

Well you use PML-8 boundary conditions everywhere (except for the ground plane) but you do not give the space of 8 cells at those directions. Thus your excitation sits behind and inside the PML. That is not a good idea... Have a look at the MSL notch filter example how it should be done using "MeasP...
by thorsten
Mon 22 Apr 2019, 21:33
Forum: Usage
Topic: Energy decay is not presented, but results are good
Replies: 4
Views: 105

Re: Energy decay is not presented, but results are good

I have not (yet) looked at your file, but the simulation is clearly unstable. The odd and very rare thing is that the instability seems to be very slow, which is very unusual...