Search found 28 matches

by rml
Wed 31 Aug 2022, 23:35
Forum: Usage
Topic: Is openEMS capable of computing the phase center for farfields?
Replies: 5
Views: 574

Re: Is openEMS capable of computing the phase center for farfields?

Sorry, I can't answer your last question.
But what interests me: Which algorithm are you implementing right now? Is there a paper about it?
by rml
Tue 30 Aug 2022, 00:35
Forum: Usage
Topic: Is openEMS capable of computing the phase center for farfields?
Replies: 5
Views: 574

Re: Is openEMS capable of computing the phase center for farfields?

Hi, two or three years ago I tried to find the phase center of an antenna using the Poynting vector method. Starting point was this paper, but unfortunately it is not freely available: HARKE, Dominic; GARBE, Heyno; CHAKRAVARTY, Prashant. A new method to calculate phase center locations for arbitrary...
by rml
Mon 15 Aug 2022, 23:18
Forum: Usage
Topic: Excitation signal - different from CST?
Replies: 6
Views: 1068

Re: Excitation signal - different from CST?

Thanks Thorsten, I was about to reply almost the same. But you was faster :)
by rml
Sun 14 Aug 2022, 23:22
Forum: Usage
Topic: Excitation signal - different from CST?
Replies: 6
Views: 1068

Re: Excitation signal - different from CST?

I think there is a simple explanation for this. The openEMS pulse shown is DC-free, that means the frequency range starts just above zero. This has the advantage that no static charges are generated which might lead to very long simulation times. For an antenna in the GHz range, a solution at exactl...
by rml
Thu 21 Jul 2022, 21:02
Forum: Usage
Topic: Ex,y,z component far-fields from CalcNF2FF
Replies: 10
Views: 2739

Re: Ex,y,z component far-fields from CalcNF2FF

Maybe I'm thinking too simply, but couldn't this approach work? You perform one simulation with the antenna and the human body model and store the fields in the area of interest near the antenna. In a second simulation run, you set all the tissue properties of the human body model to air, but don't ...
by rml
Wed 20 Jul 2022, 23:24
Forum: Usage
Topic: Ex,y,z component far-fields from CalcNF2FF
Replies: 10
Views: 2739

Re: Ex,y,z component far-fields from CalcNF2FF

I suspect there is a little confusion here. If, for example, you want to investigate the effect of electromagnetic fields on human tissue at a distance of several wavelengths from an antenna (hence already in the "far-field" region), you need the normal near-field data. But please describe what you ...
by rml
Sat 16 Jul 2022, 21:35
Forum: Usage
Topic: Whereabouts of human body models?
Replies: 2
Views: 734

Re: Whereabouts of human body models?

Hi Neil, the keyword is 'virtual family'. You could start with this: https://itis.swiss/virtual-population/virtual-population/vip2/ http://openems.de/forum/viewtopic.php?f=3&t=1118 But I have no experience with the VIP2 models by myself. One certainly also needs the tissue properties in the frequenc...
by rml
Mon 11 Jul 2022, 22:02
Forum: Usage
Topic: fieldprobes test case failing
Replies: 3
Views: 1043

Re: fieldprobes test case failing

A first addendum:
I have found "openEMS 32bit -- version v0.0.28" on my old Win7 machine. This version is about 10 years old, but also fails with the H-fields. However, figure 7 is different from the current versions.
by rml
Sun 10 Jul 2022, 22:44
Forum: Usage
Topic: fieldprobes test case failing
Replies: 3
Views: 1043

Re: fieldprobes test case failing

Hi, I can confirm that the fieldprobe test fails, both with the recently compiled version 0.0.35-76 (Linux Mint 20.3) and with version 0.0.35-74 (Win10) on a dual boot Ryzen 5600x computer. The results do not seem to differ at a first glance. However, there was one interesting difference. The test r...
by rml
Mon 06 Sep 2021, 21:33
Forum: Usage
Topic: How to understand the asymmetry of B1 on XY plane in Tutorial: MRI Loop Coil
Replies: 2
Views: 3424

Re: How to understand the asymmetry of B1 on XY plane in Tutorial: MRI Loop Coil

Hi, I did a quick search. This paper, for example, is freely available: https://mriquestions.com/uploads/3/4/5/7/34572113/b1__vs_b1-.pdf You could define the spherical phantom as air-filled for a test. Then the asymmetry should disappear. And if that works, you should be able to replicate the result...