Import near field data from a .efe
file and / or .hfe file to define a near
field data aperture. Use the near field data aperture when defining an equivalent source or
receiving antenna.
The .efe
and .hfe files do not contain
information regarding the coordinates system, frequency or number of points. As a
result, you need to supply the above information to define the near field data
aperture.
On the Construct tab, in the Define group, click the Field/Current Data icon. From the drop-down list
select Define Near Field Data.
In the Aperture data definitiondrop-down list, select one of the following:
Electric and Magnetic
field
Electric field
Magnetic field
In the Source type field, select one of the
following:
Load an ASCII text file
Note: The units are V/m
for the E-field and A/m for the H-field.
Load from *.hfe file
In the E-field file field, browse to the E-field file
location.
In the H-field file field, browse to the H-field file
location
In the Coordinate system field, select one of the
following:
The physical location of the sample points and how they relate to the
defined aperture can be specified.
[Optional] Select the Also sample along edges check box
to assume the outer sample points lie on the edges of the defined
aperture.
CAUTION:
For multiple near field sources in a single model, sample
points may not lie on any two aperture edges that share a common side. This
results in two elementary dipoles with the same location and polarisation to
be included, leading to incorrect results.
For options Cylindrical or Spherical, select the Swap source and field
validity regions check box if the fields on the inside of the
region are equivalent to the calculated field values.
In the Width (W) field, specify the aperture
width.
In the Height (H) field, specify the aperture
height.
Select one of the following:
To select near field data from multi-frequency .efe and .hfe files, select Use all
data blocks. The data is interpolated for use at the
operating frequency.
To select near field data at a specific frequency in .efe and .hfe files, select Use
specified data block number and enter the number of the
relevant data block.
To select a specific near field pattern in .efe and .hfe files, select Use
specified point range1.
In the Start reading from line number field,
specify the first line number to be read in the file.
Note: Comment
lines and empty lines are not counted.
For example, a
file with 100 points per near field, the second block starts
reading from line 101, regardless of any comment lines.
In the Number of points along U field,
specify the number of points along the U axis.
In the Number of points along V field,
specify the number of points along the V axis.
In the Label field, specify a unique label for the near
field data.
Click Create to define the near field data and to
close the dialog.
1 Near field patterns are typically
frequency-dependent and models with radiation pattern sources usually
have only a single solution frequency. If the radiation pattern is
calculated using a frequency sweep in Feko,
the .efe and
.hfe files
contain multiple patterns.