Search found 1380 matches

by thorsten
Sat 23 May 2020, 12:14
Forum: Usage
Topic: RCS with changing theta
Replies: 1
Views: 510

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: 305

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: 1293

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: 1065

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: 943

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 ...
by thorsten
Fri 03 Apr 2020, 08:46
Forum: Usage
Topic: Using multiple port
Replies: 1
Views: 780

Re: Using multiple port

In each simulation each active port is excited. If you want an s11 and s21, you have to active port 1 and deactivate port 2. For s22 and s12 you need ti do another simulation with port 2 active and port 1 inactive. If you excite port 1 and 2 and the coupling is very very small you could calculate s1...
by thorsten
Fri 03 Apr 2020, 08:01
Forum: Usage
Topic: SAR box size
Replies: 1
Views: 683

Re: SAR box size

You define the size of your (SAR) dump box as you would any dump box. Around the area that you are interested to observe your data (SAR).
by thorsten
Fri 03 Apr 2020, 07:59
Forum: Usage
Topic: Understanding lumped element
Replies: 1
Views: 852

Re: Understanding lumped element

Lots of questions. If I remember correctly the "L" part is not implemented/available for the lumped element. Only R and C. If you do not set any you get the warning and the element is ignored. As for the size, if should behave similar to reality. If it is too large it does not behave very good any m...
by thorsten
Tue 24 Mar 2020, 09:27
Forum: Usage
Topic: About the accuracy of the SAR from 3 phantom model
Replies: 2
Views: 895

Re: About the accuracy of the SAR from 3 phantom model

What is a 3 phantom model?
Have you looked at the tutorials covering SAR?
You should not use sinusexcite. It takes longer and is difficult to determine convergence.
1.5W/kg difference does not say anything....
by thorsten
Tue 24 Mar 2020, 09:25
Forum: Development
Topic: CPU affinity / speed improvement
Replies: 1
Views: 2024

Re: CPU affinity / speed improvement

Post your changes on github for me and others to review.