Search found 1425 matches

by thorsten
Mon 15 Jun 2020, 07:44
Forum: Usage
Topic: What happens if the feed is in positive Z directions and there are metallic parts touching it in the ZX plane.
Replies: 4
Views: 2902

Re: What happens if the feed is in positive Z directions and there are metallic parts touching it in the ZX plane.

Intersecting the port with metal parts is not a good idea as the port will not be able to excite a "nice" electric field. But what exactly happens depends strongly on what you are doing...
by thorsten
Mon 15 Jun 2020, 07:42
Forum: Usage
Topic: Waveguide adapter simulation
Replies: 10
Views: 6183

Re: Waveguide adapter simulation

I agree, you should just do this in the "normal" mesh. Both types of ports should work fine. You "only" need to come up with a transition. But the RWG TE01 und the CWG TE11 mode should be similar enough that this should not be too difficult?
by thorsten
Mon 15 Jun 2020, 07:39
Forum: Usage
Topic: Problem with phase accuracy in waveguide polarisers
Replies: 4
Views: 2972

Re: Problem with phase accuracy in waveguide polarisers

This sound indeed a bit surprising, but maybe you can supply your script and we can have a look? In which direction to you need this dense mesh. In all or only in direction of the waveguide or across the cross section? Do you think that the stair-casing of the waveguide boundaries are the problem? W...
by thorsten
Mon 08 Jun 2020, 18:57
Forum: Usage
Topic: Waveguide adapter simulation
Replies: 10
Views: 6183

Re: Waveguide adapter simulation

I have played with a SMA to rect waveguide transition but RWG to CWG should be interesting too and should be possible with openEMS (if that was the question). But I have not tried it yet.
by thorsten
Mon 08 Jun 2020, 18:53
Forum: Install
Topic: Installing openEMS on Ubuntu 16.04 of an AWS cloud instance possible?
Replies: 2
Views: 2504

Re: Installing openEMS on Ubuntu 16.04 of an AWS cloud instance possible?

Hi Hannes, openEMS itself only depends on the CSXCAD library and both have to interface to any GUI elements and ran run nicely on a server without any graphical interface. All you need to transfer simulation data and run openEMS is for example an SSH access. This is what I did plenty in the past. Th...
by thorsten
Sat 23 May 2020, 12:14
Forum: Usage
Topic: RCS with changing theta
Replies: 1
Views: 2258

Re: RCS with changing theta

Well the mesh usually is the main cause of long simulations. A good indication is if the excitation is already requiring a large amount of time-steps and the nyquist rate is very high too. Example for good numbers: FDTD timestep is: 9.63258e-13 s; Nyquist rate: 173 timesteps @3.00041e+09 Hz Excitati...
by thorsten
Sat 23 May 2020, 12:06
Forum: Usage
Topic: SAR for given frequency
Replies: 2
Views: 2247

Re: SAR for given frequency

I never tried, but sure. Just record and analyze SAR at different frequencies (may take a while) and use Matlab/Octave to plot in any way and combination.

regards
Thorsten
by thorsten
Sat 25 Apr 2020, 08:57
Forum: Usage
Topic: How do i plot gain vs frequency?
Replies: 2
Views: 3379

Re: How do i plot gain vs frequency?

Well first you need to record either in time-domain or at all frequencies of interest (both may require a lot of disk space).
And then calculate the nf2ff for all frequencies (may take a while).

Then you have all the data to plot pretty much everything you want over frequency...

regards
Thorsten
by thorsten
Sat 18 Apr 2020, 16:24
Forum: Usage
Topic: Convergence value
Replies: 3
Views: 3374

Re: Convergence value

The lower the remaining energy has decayed the better it is. But as jjmaloss said, sometimes e.g. static charges may get trapped and cannot decay or a high Q resonance may resonate forever (in both cases using more realistic losses may help).

regards
Thorsten
by thorsten
Tue 07 Apr 2020, 08:31
Forum: Usage
Topic: Questions on Simple_Patch_Antenna.m
Replies: 2
Views: 2850

Re: Questions on Simple_Patch_Antenna.m

s kappa the loss of the material? Is the 1e-3 part the loss tangent? Kappa is the conductivity of the material and yes the 1e-3 is the loss tangent indeed. I am not sure why it is multiplied by 2.45e9, especially when the simulation is supposed to cover +/- 1 GHz of the center frequency. If I were ...