Near-field ERROR 30233

Yevhen Saratov

I wrote the near-field to files and then created a near-field source and tried to run the calculation of the far field. I am getting the following error: 

I recorded the near field of the horn in cylindrical coordinates:

Then I created a near-field source with exactly the same parameters (as it seems to me):

Then I get the above error. Is there a problem with different coordinate systems? The point is that I tried to write the near-field source as a sphere and create the source as a sphere. But the result is the same.

Mel

You cannot write to file in one coordinate system and read from file to a different coordinate system.

But if you used spherical coordinates in both instances, there should not be a problem. Could you attach your files for the spherical coordinates case?

Eugene Saratov

Here is a variant when both are in a spherical, the same result ... If you cannot write in one and then create a source in the other, then how to write the near field of a conical horn, for example?

Mel

For the model where you are exporting the near fields, you have 30 points for the radius, running from r=0 to r=100. But where the near fields are used in an aperture, only a single point for the radius.

A Near field aperture can only be single faced, so you would need to modify the exporting to only use a single point for the radius.

If you want to look at the near fields over varying radius, then you can specify 2 near field requests, one request for the usage of the aperture with a single point for the radius (and where the efe/hfe files are exported), and the 2nd request with multiple points in radius where the exporting of the fields to file is not enabled.

Mel

For a conical horn or some geometry that is more cylindrically shaped, you could also use just a single spherical request, but is also supported to use a combination of apertures:

Let's say the conical horn pointing into the positive Z direction. Aperture 1 would be a cylindrical definition running over the length of the horn from the bottom to the opening. Then for the opening (horn's aperture) Aperture 2 would be a spherical request, but where the origin of this spherical near field request is placed some distance away from the opening, with radius chosen to be the distance from from the horn's opening to the origin. This gives an almost flat circular "end cap" aperture.