Hi, abhishek.vnit:
Thank you for your posting. On IE3D, there is a command called ENTITY->PROBE FEED TO fix. What you should do is the following:
1. Define the BASIC PARAMETERS for the substrates and the meshing parameters.
2. Draw your fix on top of the substrate. For example, assume your substrate is 30 mils. You draw your fix (any shape) as a group of polygons.
3. Select INPUT->KEY IN ABSOLUTE LOCAITON. Enter the exact location of your probe at (X0, Y0, 30). MGRID may complain the entered vertex is inside the fix. However, pelase ignore it and keep the entered vertex there.
4. Then, you can select ENTITY->PROBE FEED TO fix. Please change the probe-radius to the correct value you want. Select OK and the structure is ready to simulate. IE3D's probe-feed model is very accurate. Best regards.