# Spherical Modes

This option defines an ideal receiving antenna with spherical modes.

## Parameters:

Request name
The name of the request.
Mode data source
The spherical modes can be entered directly in the .pre file or it can be imported from a TICRA (.sph) file.
X, Y, Z position
The coordinates of the origin r = 0 of the mode in metres. (These values are optionally scaled by the SF card.)
If this option is selected, you can specify TE-mode (s = 1) or TM-mode (s = 2) and the indices m and n in the group below. Here n is the mode index in the radial direction and must be in the range 1, 2, . . . $\infty$ and m is the mode index in the azimuth direction $\phi$ . There is no distinction between even and odd modes (with $\mathrm{cos}\left(m\phi \right)$ and $\mathrm{sin}\left(m\phi \right)$ angular dependencies), but rather use the angular dependency ${e}^{jm\phi }$ . Thus the index m can also be negative, but it must be in the range -n . . . n.
(1) $j=2\phantom{\rule{thinmathspace}{0ex}}\left[n\phantom{\rule{thinmathspace}{0ex}}\left(n+1\right)+m-1\right]+s$
Magnitude of the mode in $\sqrt{W}$
Absolute value of the complex amplitude of this specific spherical mode (due to the applied normalisation of the spherical modes, the unit of this amplitude is $\sqrt{W}$ = $\sqrt{VA}$ ).