# Near Field Parameters

## Near-Field Panel

Go to the Setup tab in the main window. Then, select the Near-Field panel.

The near field can be computed after having calculated the current distribution previously. Thus, the parameters set in the Near-Field panel have no effect in the determination of the currents and can be set at any time. However, the near field must be recalculated every time these parameters are modified. The Near-Field panel has three options: *Cartesian*, *Cylindrical*, and *Spherical*. By choosing one of these options near-fields can either be calculated in Cartesian, Cylindrical or Spherical coordinates.

### Cartesian Coordinates

If the **Cartesian** option is chosen, the following parameters can be set for near-field calculations, Fig. 1:

**Origin**** (X0,Y0,Z0)**

It is the origin of the Cartesian coordinates used to define the observation points where near fields will be calculated.

**X**

This box is used to set x-coordinates of the observation points where near-fields will be calculated. The start, step and stop x-coordinates must be set. Start and stop x-coordinates are measured from X0.

**Y**

This box is used to set y-coordinates of the observation points where near-fields will be calculated. The start, step and stop y-coordinates must be set. Start and stop y-coordinates are measured from Y0.

**Z**

This box is used to set z-coordinates of the observation points where near-fields will be calculated. The start, step and stop z-coordinates must be set. Start and stop z-coordinates are measured from Z0.

### Cylindrical Coordinates

If the **Cylindrical** option is chosen, the following parameters can be set for near-field calculations, Fig. 2:

**Origin (X0,Y0,Z0)**

It is the origin of the Cylindrical coordinates used to define the observation points where near fields will be calculated.

**R**

This box is used to set the distances or R-coordinates of the observation points where near-fields will be calculated. The start, step and stop R-coordinates must be set. Start and stop distances or R-coordinates are measured from the origin (X0,Y0,Z0).

**Phi**

This box is used to set the azimuth angles or phi-coordinates of the observation points where near-fields will be calculated. The start, step and stop phi-coordinates must be set in degrees.

**Z**

This box is used to set the z-coordinates of the observation points where near-fields will be calculated. The start, step and stop z-coordinates must be set.

### Spherical Coordinates

If the **Spherical** option is chosen, the following parameters can be set for near-field calculations, Fig. 3:

**Origin (X0,Y0,Z0)**

It is the origin of the Spherical coordinates used to define the observation points where near fields will be calculated.

**R**

This box is used to set the distances or R-coordinates of the observation points where near-fields will be calculated. The start, step and stop R-coordinates must be set. Start and stop distances or R-coordinates are measured from the origin (X0,Y0,Z0).

**Theta**

This box is used to set zenith angles or theta-coordinates of the observation points where near-fields will be calculated. The start, step and stop theta-coordinates must be set in degrees.

**Phi**

This box is used to set azimuth angles or phi-coordinates of the observation points where near-fields will be calculated. The start, step and stop phi-coordinates must be set in degrees.