Hi Brain,
Based on the limited information I can suggest a general workflow.
To simulate 3D dielectric structures with a metal feed in MATLAB, you can use the Finite Difference Time Domain (FDTD) method, which is a numerical method frequently used in electromagnetic simulations.
The FDTD method discretizes the space into a grid of cells, and the electromagnetic field is represented by time-dependent electric and magnetic fields on each grid point. The simulation is carried out by updating the electric and magnetic fields in each grid point based on Maxwell's equations and the material properties at each point.
To simulate a concentric dielectric spherical shell, you can define the dielectric structure as a cylindrical or spherical coordinate system. Then, you can map the dielectric constants onto the grid points and set the metal feed as a boundary condition.
Keep in mind that simulating 3D structures with FDTD can be computationally intensive and require significant computational resources. Therefore, it may be necessary to optimize the simulation parameters, such as the grid size and time step, to achieve accurate and efficient results.
Further, for more information you can kindly go through the examples listed in the below link.
with regards,
Gokul Nath SJ
