Hi, Antenna_abc:
There are 2 ways for it.
(1) Add one or multiple of your .geo files into MODUA as geometry modules. Add necessary lumped components (s-parameters, R, L, C, etc) as necessary and connect them. Simulate it with pattern calculation enabled. You will get the pattern parameters with all teh components connected.
(2) On MGRID/IE3D, you simulate a geometry with .cur file created or .mpa (general patterns) created. MODUA will be invoked with the s-parameters dispalyed. Add necessary components into the MODUA and connect them. Select PROCESS->SIMULATE AND FIND EXCITATIONS and provide necessary excitations. Select File->Save Excitations into an .ECT file. Then, on PATTERNVIEW, you can select PROCESS GENERAL PATTERN. Selec the .MPA file. You can attach the .ect file into the .MPA file and select FIND PATTERN to find the pattern with the specified excitations defined in the .ECT file. In this way, the radiaiton powers and patterns will be the same as the (1). However, please remember the gain and the efficiency are not the same. This is due to the fact that the pattern calculated in this way does not account for the lumped elements you put on them in MODUA. It will only consider the structure as a system. The 1st way will consider the whole thing on MODUA as the system.
Best regards,