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.)

Rotation about axes

The rotation of the spherical mode source about the X, Y and Z axes.

Number of modes

Specify the number of modes that will be entered in the .pre file.

Traditional index smn

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 $\cos (m\phi )$ and $\sin (m\phi )$ 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.

Compressed index j

With this option, a compressed one-dimensional mode numbering scheme is used. The Mode index j is then specified as

(1) $j=2[n(n+1)+m-1]+s$

where s = 1 for TE-mode and s = 2 for TM-mode. This unified mode numbering scheme allows the computation of an extended scattering matrix (with network and radiation ports). This index j then represents a unique port number in the scattering matrix.

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 $\sqrt{W}$ = $\sqrt{VA}$ ).

Phase of the mode

The phase of the complex amplitude of this spherical mode in degrees.