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.
Position (coordinate)
The coordinates of the origin r = 0 of the mode in metres. These values are optionally scaled by the SF card.
Rotation about the 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 (degrees)
The phase of the complex amplitude of this spherical mode in degrees.
Use all data blocks
Import all data blocks from the specified TICRA (.sph) file. The data is interpolated for use at the operating frequency.
Use only specified data block number
Use the data from the nth frequency block in the TICRA (.sph) file.