Search found 170 matches

by Hale_812
Tue 30 Jun 2020, 07:41
Forum: Usage
Topic: usage of different prio is giving entirely different return loss curve!
Replies: 4
Views: 210

Re: usage of different prio is giving entirely different return loss curve!

that's weird. As far as I understand, the engine treats every cell separately, regardless of continuity. First, I would check the metal definition. It may happen that one is a metal, and another is PEC, or something like that. It may happen also that the air, or substrate has a surpassing priority, ...
by Hale_812
Wed 17 Jun 2020, 03:40
Forum: Usage
Topic: Waveguide adapter simulation
Replies: 10
Views: 695

Re: Waveguide adapter simulation

I guess, you are transiting From Rect to circ, and not back? so, isn't it obvious?

Or (probably), knowing approximate impedance you can add a lumped port along the expected field line corresponding the mode. It just creates a E field by driving the current through the port resistor.
by Hale_812
Tue 16 Jun 2020, 09:22
Forum: Usage
Topic: Corrugated Horn Antenna Tutorial for openEMS
Replies: 6
Views: 4348

Re: Corrugated Horn Antenna Tutorial for openEMS

I think, adding PML after the model and mesh is generated is a correct way. Calculating pml during mesh generation always creates troubles. I prefer making a model first, with an array of important structural nodes. Optimize the nodelist by removing duplicate nodes, and coordinate points within mini...
by Hale_812
Mon 15 Jun 2020, 01:40
Forum: Usage
Topic: Problem with phase accuracy in waveguide polarisers
Replies: 4
Views: 336

Re: Problem with phase accuracy in waveguide polarisers

the answer is in your question. circular waveguide requires non-orthogonal meshing
by Hale_812
Thu 11 Jun 2020, 08:56
Forum: Usage
Topic: Waveguide adapter simulation
Replies: 10
Views: 695

Re: Waveguide adapter simulation

Cylindrical coordinates can not be combined with rectangular. You will get stepped surface either in circular, or rectangular section. And it is easier to define circular section in rectangular coordinates, then the opposite.
by Hale_812
Wed 10 Jun 2020, 03:37
Forum: Usage
Topic: Waveguide adapter simulation
Replies: 10
Views: 695

Re: Waveguide adapter simulation

The model of coax to feeding rect-horn works, but needs so dense mesh, that you better put a lumped port just inside the rect. section. Septum transition should also work just fine, but the circular waveguide is a problem. You will die increasing the mesh for accurate curved surface representation. ...
by Hale_812
Wed 10 Jun 2020, 03:28
Forum: Usage
Topic: Feed excitation
Replies: 2
Views: 288

Re: Feed excitation

Feed is a transmission line connecting the device of interest to power source. You, probably mean a port. In general, most ports are voltages over a load block in OpenEMS, except plane wave excitation, which is represented by a cube with boundaries pulling a plane inside, and cancelling it outside, ...
by Hale_812
Thu 28 May 2020, 02:27
Forum: Usage
Topic: Tutorial: Patch_Antenna_Phased_Array
Replies: 1
Views: 1135

Re: Tutorial: Patch_Antenna_Phased_Array

seems like OS path problem. Avoid national characters, long file location strings. something like C:\project\prj1\ is a good choice.

don't forget to change the active directory in Octave/Matlab when executing.
by Hale_812
Mon 02 Mar 2020, 05:59
Forum: Usage
Topic: What is the relation of amplitude returned by harminv() to abs(fft(voltage)) ?
Replies: 3
Views: 2741

Re: What is the relation of amplitude returned by harminv() to abs(fft(voltage)) ?

As I mentioned it, yes. And I did not find anything useful there; it just calls the binary program, and I don't know what's inside.

Harminv does not have any user-oriented documentation, except a basic explanation that it is cooler than FFT. Actually, I could not find technical documentation either.