Spherical Modes

This option defines an ideal receiving antenna with spherical modes.

Figure 1. The RA - Receiving antenna dialog.


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, . . . and m is the mode index in the azimuth direction φ . There is no distinction between even and odd modes (with cos ( m φ ) and sin ( m φ ) angular dependencies), but rather use the angular dependency e jmφ . 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 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 W = V A ).
Phase of the mode
The phase of the complex amplitude of this spherical mode in degrees.