MoM/MLFMM-PO
Applicability of method
The EfieldFD MoM-PO and MLFMM-PO solvers are suitable for analysis of very large problems where the electrical size is to large for MoM or MLFMM. Typical applications include
- Radar cross section (RCS) analysis
- Antenna integration on large structures
- Reflector antenna design
Description of method
The MoM-PO and MLFMM-PO solvers use a domain decomposition of the problem into a MoM or MLFMM domain and a PO domain. In Figure 1 two examples of domain decomposition are shown for (left) a reflector antenna and (right) a UAV. In the Efield® mesh generation a tool for creating curvature based decompositions and detection of free edges are included which makes it easy for the user to create a suitable decomposition for the MoM-PO or MLFMM-PO solvers.
The EfieldFD MoM-PO and MLFMM-PO solvers are based on an iterative technique between the MoM or MLFMM and PO domain. First a solution is computed in the MoM or MLFMM region using the MoM or MLFMM solver. After this solution has been computed a solution in the PO region is solved for using the MoM or MLFMM solution as a source together with the excitation. After the PO solution has been computed a new solution is computed in the MoM or MLFMM region using the MoM or MLFMM solver with the PO solution as a source together with the excitation. The procedure is continued until convergence or until a preset number of iterations has been reached.
When using the MoM-PO or MLFMM-PO large savings in memory and solution time are acheived since we instead of solving the whole problem with MoM or MLFMM we solve one smaller MoM or MLFMM problem and one smaller PO problem.
Figure 1: MoM/MLFMM-PO decomposition of UAV
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Solver features
Material and Boundary conditions
In the PO domain only PEC are allowed. In the MoM or MLFMM region the following material and boundary conditions are available.
- Dielectric and magnetic materials, lossy and lossfree
- PEC
- PMC
- IBC
- RBC
- Lumped elements (RLC)
Excitations
Available excitations in the EfieldFD MoM-PO and MLFMM-PO solvers are:
- Plane wave
- Dipole
- Voltage excitations on surface edges
- Waveguide mode excitations using 2D numerical or analytical eigenmode solver
- General field distributions
Post-processing
Output from the MoM-PO and MLFMM-PO solvers includes:
- S-parameters
- Input impedance
- SVWR
- Reflection loss
- Far fields (2D, 3D, directivity, gain, field pattern, polarisation,...)
- Radar Cross section (RCS) calculation, bistatic and monostatic
- Near fields
- Surface and wire currents
- Far field power
- Power through user defined surfaces