.mat file size of unit cell using periodic boundary condition

Sev Öz

Hi to all,

I am trying to get the impedance matrix of a unit cell using periodic boundary condition (PBC) in Feko using Surface Equivalance Principle. I normally get impedance matrix  for structures without PBC but for unit cell not. In the .out file of unit cell, the information of the cell is given below and the unknown number is computed as 2942 but the "Memory requirement for MoM matrix: 2944 rows * 2942 columns" is computed. Why the MMxNN size is larger than unknown number? Is there any other stored information in Zmn? I could not understand the difference? And in my impedance matrix, left upper part (I think impedance submatrix for PEC unknowns) has zeros for some matrix elements?  Does it occur because of this excess memory requirement? If you could help me, thanks  alot.

Sev Oz  

 

 

"Memory requirement for MoM matrix: 2944 rows * 2942 columns = 8661248 complex numbers"

DATA FOR MEMORY USAGE

Number of metallic triangles: 630 max. triangles: MAXNDR = 1050
Number of dielectric triangles: 360
Number of aperture triangles: 0
Number of RL-GO triangles: 0
Number of windscreen triangles: 0
Number of FEM surface triangles: 0
Number of modal port triangles: 0
Number of metallic segments: 0 max. segments: MAXNSEG = 0
Number of combined MoM/MTL segments: 0
Number of dielectr./magnet. cuboids: 0 max. cuboids: MAXNQUA = 0
Number of tetrahedra: 0 max. tetrahedra: MAXNTETRA = 0
Number of edges in PO region: 0 max. edges: MAXPOKA = 0
Number of wedges in PO region: 0 max. wedges: MAXPOKL = 0
Number of Fock regions: 0 max. Fock regions: MAXFOGE = 0
Number of polygonal surfaces: 0 max. surfaces: MAXPOLYF = 0
max. corner pts.: MAXPOLYP = 0
Number of UTD cylinders: 0

Number of metallic edges (MoM): 1862 unknown: 1862 (electr.) max. edges: MAXNKA = 2416
0 unknown: 0 (magnet.)
Number of metallic edges (PO): 0 unknown: 0 (electr.)
unknown: 0 (magnet.)
Number of dielectric edges (MoM): 554 unknown: 554 (electr.)
526 526 (magnet.)
Number of dielectric edges (PO): 0 unknown: 0 (electr.)
unknown: 0 (magnet.)
Number of aperture edges (MoM): 0 unknown: 0 (magnet.)
Number of edges FEM/MoM surface: 0 unknown: 0 (electr.)
0 0 (magnet.)
Number of nodes between segments: 0 unknown: 0 max. nodes: MAXNKNO = 0
Number of connection points: 0 unknown: 0 max. conn.: MAXNV = 0
Number of dielectric cuboids: 0 unknown: 0 max. cuboids: MAXNQUA = 0
Number of magnetic cuboids: 0 unknown: 0
Number of dielectric faces (VEP): 0 unknown: 0
Number of magnetic faces (VEP): 0 unknown: 0

Number of basis funct. for MoM: 2942 unknown: 2942 max. basisf. MAXNZEILE = 2942
Number of basis funct. for PO: 0 unknown: 0 max. basisf. MAXNKAPO = 0

 

Mel

The leading dimension of the MoM matrix is always rounded up to the next multiple of 16 - this has to do with memory management and performance.

The additional memory allocated is very small (2 * 2942 * 16 Byte = 94 kByte)

Note that the real data Feko operates on is still only the square MoM matrix.

I.e. Feko does not introduce any zero matrix elements or similar.