DataSet Structure: Near Field

Near field results must contain a complete set of either electric field components, magnetic field components, or both in order to be valid.

For each different coordinate system, a different set of spatial axes are required. See Table 1 for the required properties for near fields.

Table 1. Required properties for near fields.
Property name Property type Description
Frequency Axes Every near field requires a valid frequency axis. (Hz)
Axis 1...3 Axes Every near field requires three independent spatial axes. Depending on the coordinate system, these axes may vary. Table 2 gives a breakdown of the required axes for each system.
MediumNames Axes The value is an index into the MediumNames table in the MetaData section of the DataSet.
EFieldComp1...3 Quantities Required quantity set for electric fields. All three complex values must be defined for a complete electric field definition. ( $\frac{V}{m}$ )
HFieldComp1...3 Quantities Required quantity set for magnetic fields. All three complex values must be defined for a complete magnetic field definition. ( $\frac{A}{m}$ )
MediumIndex Quantities A scalar quantity that links to the list of media names under the MetaData list MediumNames
Conical MetaData A boolean flag indicating whether the near field is defined in a conical coordinate system. The value may be either true or false.
MediumNames MetaData A list of names for the media in which a near field point was calculated. An index to this list is provided for each point under the MediumIndex quantity.
Origin MetaData The local origin for the workplane around which the near field is defined.
UVector MetaData A point relative to the origin which indicates in which direction the $u$ vector.
VVector MetaData A point relative to the origin which indicates in which direction the $v$ vector.
RhoStepSize MetaData A scalar value indicating the increment with which the cone’s rho axis increases. This effectively controls the angle of the cone for a conical system.
Note: Only required if Conical is true.
Note: The conical coordinate system is an exception. Since it is technically not a complete coordinate system, additional information is required.
For near fields defined in the conical coordinate system, the following must also be provided under the MetaData fields:
Conical = true
This flag indicates to POSTFEKO that the DataSet fields must be interpreted differently than other coordinate systems.
RhoStepSize
The step size indicates the intervals with which the rho axis grows.f
Note: The rho axis only contains a single value which corresponds to the starting point of the cone.
Table 2. Coordinate system axes.
Coordinate system Axis 1 Axis 2 Axis 3
Cartesian X Y Z
Spherical R Theta Phi
Cylindrical (X axis) Rho Phi X
Cylindrical (Y axis) Rho Phi Y
Cylindrical Rho Phi Z
Conical Rho Phi Z