Surrounding Electromagnetic Field

Item

Notes

Graph type

Selectable from XY Graph and Polar Graph. The polar graph is available only if the angle is selected for the horizontal axis.

Observation Point

Specify the position of the observation point by angle and distance. If polar coordinates selected at [Setting > Other]-[Coordinate System], the position is designated in (r,θ,φ),

and if cylindrical coordinate system selected, the position is designated in (ρ,φ,z).

Refer to the diagram in the lower right of the dialog box for the meaning of each variable.

Calculation of Electromagnetic Directivity in Femtet

Calculates rE as described in [Electromagnetic Waves Directivity]. The electric field is given by dividing rE by the distance between the origin and the observation point.

Display

If E [V/m] or H [A/m] selected, calculates complex amplitudes. Reference: How to Examine the Results of Harmonic Vibration

If y [V/m] is given, it can be converted to x [dBuV/m] by 20*log(|y|*1.0e6/1.414).

1.414 is used to convert the amplitude into the effective value.

Reference: 0 [dBµV/m] corresponds to an electric field strength of 1 [µV/m] RMS.

Plane of Symmetry and Infinite Ground Plane

See [Electromagnetic Waves Directivity].

Selectable from θ, φ, and Frequency for the horizontal axis of XY graph and for the rotation angle of the polar graph.

When Frequency is selected, the maximum electric field at the observation point will be plotted for the frequencies.

Option: Coordinate system

Selectable from Polar coordinates and Cylindrical coordinates.

Option: Input method

Selectable from Number of Divisions and Interval.

Option: Complex number type

Option: Use far field

Calculates the equation which is given based on the assumption that the observation point is in the far field. The calculation accuracy will decrease in the near field, but the calculation will take less time.