Ansys Near Field Data File
The data file that you select when you click Create External Design of the Incident Wave Source dialog box is in the *.and format. The *.and file describes the location and contents of one or more Ansys Near Field Data Files which are in the *.nfd format. If no units are specified for spherical, cylindrical, or Cartesian coordinates, the *.ndf files use SI units of radians and meters respectively. You can append units, such as mm or deg, as needed for each coordinate value.
An example of a *.and file is shown below, followed by examples of .nfd files with Cartesian and Cylindrical coordinate systems. The File format specification is provided in Technical Notes: Ansys Near Field Description Format Specification.
Sample *.and File Sphere Geometry
$begin 'NearFieldHeader'
type = 'nfd'
geometry = 'sphere'
center = '0mm, 0mm, 0mm'
radius = '20mm'
fsweep='1GHz, 10GHz'
$end 'NearFieldHeader'
$begin 'NearFieldData'
FreqData("1GHz", "exportfields-1GHz.nfd")
FreqData("2GHz", "exportfields-2GHz.nfd")
FreqData("3GHz", "exportfields-3GHz.nfd")
FreqData("4GHz", "exportfields-4GHz.nfd")
FreqData("5GHz", "exportfields-5GHz.nfd")
FreqData("6GHz", "exportfields-6GHz.nfd")
FreqData("7GHz", "exportfields-7GHz.nfd")
FreqData("8GHz", "exportfields-8GHz.nfd")
FreqData("9GHz", "exportfields-9GHz.nfd")
FreqData("10GHz", "exportfields-10GHz.nfd")
$end 'NearFieldData'
This example is a simple text file and saved with the .and extension. It is clear from the sample that the near field data was generated on a sphere centered at the origin and radius = 20mm for frequencies 1 GHz through 10 GHz. For the sample *.and file 10 *.nfd files are specified so 10 *.nfd files were generated. Examples of such Ansys Near Field Data Files (exportfields-1GHz.nfd) are shown below.
Users can also use external data in the field format of J and M, J only and M only.
Sample *.and File, Cylinder Geometry
The following example shows a *.and file using a Cylindrical Coordinate System
$begin 'NearFieldHeader'
type='nfd'
fcoords='cylindrical'
geometry='cylinder'
center='0mm,0mm,0mm'
axis='0,0,1'
radius='20mm'
height='258mm'
fsweep='1GHz'
$end 'NearFieldHeader'
$begin 'NearFieldData'
FreqData("1GHz", "fields_cylinder.nfd")
$end 'NearFieldData'
Sample NFD File in Cartesian Coordinate System
The sample below shows the near field data that the *.nfd file contains. The file uniquely specifies the position of several points (700 in this case) and the real and imaginary values of the E field and H field vectors at these points along the x, y, and z axes in the Cartesian Coordinate system.
#Index, X, Y, Z, Ex(real, imag), Ey(real, imag), Ez(real, imag), Hx(real, imag), Hy(real, imag), Hz(real, imag)
Frequencies 5
Frequency 1.000000e+009
1, 0, 0, 0.02, 0.0938, -0.1140, -0.0136, -0.0132,
-0.6038,
-0.4006, 0.0004, -0.0004, -0.0006, -0.0008, -0.0037, 0.0038
....... ....... ....... ....... ....... .......
....... ....... ....... ....... ....... .......
700, 2.1e-018, -1.2e-018, -0.02, 0.0839, -0.1080,
-0.0125,
-0.012, -0.0213, 0.1423, -0.0002, 0.0002, 0.0003, 0.0009,
-0.003, 0.0032
Frequency 5.000000e+009
....... ....... ....... ....... ....... .......
....... ....... ....... ....... ....... .......
Sample NFD File in Spherical Coordinate System
The sample below shows the near field data that the *.nfd file contains. The file uniquely specifies the position of several points (700 in this case) and the real and imaginary values of the E field and H field vectors at these points along the r, theta, and phi directions in the Spherical Coordinate system.
#Index, Theta, Phi, Er(real, imag), Etheta(real, imag), Ephi(real, imag), Hr(real, imag), Htheta(real, imag), Hphi(real, imag)
Frequencies 5
Frequency 1.000000e+009
1, 0.000000e+000, 0.000000e+000, -1.835144e-001, -1.822055e-001, -2.648018e-002, -2.096681e-001, -1.281892e-001, -5.361222e-002, 1.279651e-004, -1.016122e-004, 6.289402e-004, -6.598072e-004, -1.281892e-001, -5.361222e-002
....... ....... ....... ....... ....... .......
....... ....... ....... ....... ....... .......
700, 3.141593e+000, 5.759587e+000, -1.282983e-001, -1.141968e-001, -2.207641e-001, -9.119582e-002, -2.669357e-001, -1.063323e-001, 6.827586e-005, -9.142062e-005, 1.030250e-003, -1.406250e-003, -2.669357e-001, -1.063323e-001
Frequency 5.000000e+009
....... ....... ....... ....... ....... .......
....... ....... ....... ....... ....... .......
....... ....... ....... ....... ....... .......
Sample NFD File in Cylindrical Coordinate System
#Index, Rho, Phi, Z, Erho(real, imag), Ephi(real, imag), Ez(real, imag), Hrho(real, imag), Hphi(real, imag), Hz(real, imag)
Frequencies 1
Frequency 1.000000000000000e+009
1, 2.0e+01mm, 0.0000000000000000e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
2, 2.0e+01mm, 0.7853981633974483e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
3, 2.0e+01mm, 1.5707963267948966e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
4, 2.0e+01mm, 2.3561944901923449e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
5, 2.0e+01mm, 3.1415926535897931e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
6, 2.0e+01mm, 3.9269908169872415e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
7, 2.0e+01mm, 4.7123889803846897e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
8, 2.0e+01mm, 5.4977871437821382e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
9, 1.0e+01mm, 0.0000000000000000e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
10, 1.0e+01mm, 0.7853981633974483e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
11, 1.0e+01mm, 1.5707963267948966e+000, -1.29e+2mm, 1,0, 1,0, 1,0, 1,0, 1,0, 1,0
...