CADFEKO and POSTFEKO have a powerful, fast, lightweight scripting language integrated into the application that allows you to create models,
get hold of simulation results and model configuration information and much more.
A mesh of surface triangles in the shape of a flat parallelogram can be created with this card. In general, this card
is replaced by the PM card. This card should only be used when the user wants to force the very regular meshing that
this card produces.
The CB card can be used to change geometry element labels that have been previously defined. Labels that are associated
with points, segments, triangles, cuboids, polygonal plates and tetrahedral elements can be updated.
Domain decomposition can be used to store parts of a モーメント法 solution in a file to be reused in future simulations. The stored part must remain static but the rest of the model
can change.
The DP card is used to define points in space. These points are used to define the extent and orientation of other geometric
entities and to locate excitations.
The DZ card is used to create a cylindrical shell, meshed into cuboidal elements for using the volume equivalence principle
in the method of moments. The meshing parameters as set at the IP card are used, and the medium as set at the ME card
is assigned to all created cuboidal elements.
The FM card is used to instruct the Feko solver to calculate the solution using accelerated methods, for example, using the multilevel fast multipole method (MLFMM) or adaptive cross-approximation (ACA). An option is available to apply compression to looped plane wave sources.
Options related to the Feko solution parameters is set using the FP card. The basis functions used when using FEM or MoM is set globally or on specific labels.
The IN card is used to include external files. These files may be other .pre files (which are included as if they were part of the master file) or mesh data files containing wire segments, triangles,
quadrangles, tetrahedral volume elements and/or polygonal plates (in FEMAP neutral, ASCII format, NASTRAN, AutoCAD DXF,
NEC model, CONCEPT geometry, STL, PATRAN neutral, ANSYS CDB, ABAQUS, GiD or I-DEAS UNV mesh files).
This card creates a mesh of surface triangles in the shape of circular region with or without a hole. It is also possible
to create an elliptical region.
With this card, a modal port boundary condition may be applied on the boundary of a 有限要素法 (FEM) region. A modal port essentially represents an infinitely long guided wave structure (transmission line) connected to
a dielectric volume modelled with FEM.
This card must be used to distinguish the different media and to create segments and triangles (metallic or dielectric)
within or on the surface of dielectrics solved with FEM or VEP as well as MoM/MLFMM.
The PH card creates a triangular or quadrangular plate with a circular or elliptical hole as shown in the card. The hole
can be used, for example, to attach a cylinder (ZY card) to the plate and it can be filled with the KR card.
A surface mesh of triangles in the shape of a polygon is created by using the PM card. The PM card also allows the specification
of interior mesh points. The PM card should generally be used in favour of other cards that create flat surface meshes
with straight edges.
The RM card provides a sophisticated remeshing and adaptive mesh refinement facility. Most types of meshes (surface mesh
with triangular patches, wire segment mesh, cuboidal volume elements) created by any option supported in Feko (for example, direct creation in PREFEKO with cards, but also import from NASTRAN, FEMAP, PATRAN and the rest) can be used as a basis, and one can then apply
either a local or a global mesh refinement. Unfortunately in Feko Suite 5.4 there is still a restriction that tetrahedral volume elements as used for the FEM cannot be refined with the RM card.
With the TG card, the already entered geometric elements (triangles, segments and the rest) can be translated, rotated,
mirrored and/or scaled. It is also possible to duplicate structures.
This card defines the parameters for the 回折均一理論 (UTD) for polygonal plates and cylinders, faceted UTD for curved surfaces and レイランチング法に基づく幾何光学法 (RL-GO).
The WA card is used to define all windscreen antenna solution elements. This would include all elements in close proximity
to the finite glass structure and can consist of either segments or triangles (all defined by labels).
The WR card is used to define a dielectric windscreen reference plane. Geometrically this surface is not part of the electromagnetic
model and is used simply to determine the curvature factor between the two elements on the windscreen.
When meshing a model, you can either use the automatic meshing algorithm to calculate the appropriate mesh settings
or you can specify the mesh sizes. When you specify the mesh sizes, the mesh sizes should adhere to certain guidelines.
Feko integrates with various products within Altair Simulation Products such as HyperStudy. Integration with third-party products is also supported through the powerful scripting and plug-in infrastructure.
Feko creates and uses many different file types. It is useful to know what is stored in the various files and weather they were
created by Feko and if it is safe to delete them. The files are grouped as either native files that have been created by Feko or non-native files that are supported by Feko. Non-native files are often exported by Feko even if the formats are not under the control of the Feko development team.
A mesh of surface triangles in the shape of a flat parallelogram can be created with this card. In general, this card
is replaced by the PM card. This card should only be used when the user wants to force the very regular meshing that
this card produces.
A mesh of surface triangles in the shape of a flat parallelogram can be created with
this card. In general, this card is replaced by the PM card. This card should only be used
when the user wants to force the very regular meshing that this card produces.
On the Construct tab, in the Surfaces group,
click the Plate (BP) icon.
Figure 1. The BP - Specify a parallelogram dialog.
Parameters:
S1, S2, S3, S4
The points S1 to S4 are the four corner points of the parallelogram. These points
should have been defined previously with DP cards.
Specify non-uniform meshing
Normally, a parallelogram is segmented according to the edge length specified with the
IP card. When creating small microstrip lines, it may be desirable to use a finer
segmentation in one direction. Check this item if a finer segmentation is required in
one direction. The mesh sizes are in m and are scaled by the SF card.
Mesh size along sides a and c
Edges S1-S2 and S3-S4
Mesh size along sides b and d
Edges S2-S3 and S4-S1
The points are connected in the order that they appear in the BP card. Thus the user has
to ensure that the points describe a parallelogram. If this is not the case, then PREFEKO
will abort with the appropriate error message.
The direction of the normal vector of the subdivided triangles is determined by the right
hand rule through all corners. This direction is only important when used with 物理光学法 (PO card), dielectrics (ME card), or with the 混合界形積分方程式 (CF card).
Example of BP card usage
The BP card can be used to create a plate with uniform meshing:
Figure 2. Example a uniformly meshed parallelogram created with the BP card .
The BP card can be used to create a plane with non-uniform meshing:
Figure 3. Example a non-uniformly meshed parallelogram created with the BP card.