EMAP5 BOOKKEEPING SCHEME AND INPUT/OUTPUT FORMATThe input file generated by SIFT5 contains the information about the structure in eleven parts as follows:
Details of each part are described below. GLOBAL INFORMATION TABLEParameters in the global information table are shown in
Table III. These parameters are used in EMAP5 and SIFT5 to
dynamically allocate memory for other tables. Those values
are printed out to the input file in the order shown in the
table. Table III. Global information table.
GLOBAL NODE TABLE
The global node table stores the coordinates of all nodes.
A unique node number, starting with one, is assigned to
each node. The matrix NodeCord[TotNodeNum][3] stores
the global node table in EMAP5 and SIFT5. Each row of the
matrix stores the x, y
and z coordinates of one node. For example, NodeCord[i][0] stores the x coordinate of the node i+1. NodeCord[i][1] stores the y coordinate of the node i+1. NodeCord[i][2] stores the z coordinate of the node i+1. The matrix NodeCord[TotNodeNum][3] will be
written to the input file after SIFT5 terminates. GLOBAL EDGE TABLE
An edge is defined as a vector from one node (startnode)
to another node (endnode). A unique edge number, starting
with one, is assigned to each edge. The edge table is
stored in the matrix GlobalEdgeEnds[TotEdgeNum][5].
Table IV shows the data associated with edge i+1. These
parameters used by SIFT5 and EMAP5, will be written to the
input file by SIFT5.
All edges are classified into six categories as follows: 1. Inner Edges Inner edges are located within the FEM region but not one the surface. They will be included in the finite element matrix A. 2. Dielectric Edges Dielectric edges are located on the dielectric surface S_{d}. They will be included in the A, B_{dd,} D_{dd} and D_{cd} matrices. 3. Metal Edges Metal edges are located on the metal surface S_{c} of the structure. They will be included in the C matrix. 4. HalfMetal/HalfDielectric Edges Halfmetal/halfdielectric edges are located between the metal surface and dielectric surface. Boundary conditions can be enforced using the method discussed in Section II. 5. Hybrid Edges Hybrid edges include dielectric edges and halfmetal/halfdielectric edges. Hybrid edges will be included in both A and C matrices. The FEM and MoM equations are coupled though these hybrid edges. 6. Contour Metal Edges Contour metal edges have three characters: First, they are metal edges. Second, they are located outside the FEMMoM boundary. Third, they are located on the contour of the patch conductor. The surface currents across the contour metal edges are zero. Thus, these edges are not included in FEM and MoM matrices.
Table IV. Global edge table for edge i+1.
TRIANGLE TABLE
A triangle can be uniquely determined by its three nodes or
three edges. For convenience in EMAP5, SIFT5 provides both
descriptions in the input file. The matrix
TrngleNode[TotTrngleNum][3] stores the coordinates
of all triangles . The matrix
TrngleEdge[TotTrngleNum][3] stores all edge
information for the triangles. The parameters shown in the
Table V are used in both SIFT5 and EMAP5. Their values are
written to the input file by SIFT5.
The sequence of the nodes is chosen according to the righthand rule with respect to the triangle's normal vector. The normal vector is defined as the unit vector pointing outward from the FEM region. There are three possible ways t o store the nodes. The local directions of the edges are determined by the righthand rule. The matrix TrngleEdge[ ] [ ] stores the local edge system. The local edge system is represented in terms of the global edge system, which is defined by t he matrix GlobalEdgeEnds[ ][ ]. If the local direction of one edge does not coincide with the global direction, a minus sign will be assigned to that edge. Otherwise, a plus sign will be assigned. An example to show how local and global edge systems work is given below. Illustrated in Figure 16, a triangle contains three nodes 1, 2, and 3. The global edges defined in GlobalEdgeEnds[ ][ ] are edge 4, 5 and 6 with the direct ions shown by arrows. Suppose the normal vector goes inside and the triangle number of this triangle is 1. Either of the three combinations in Table VI is valid.
Table V. Edge and node table for triangle i+1.
Figure 19. A triangle and its normal vector.
Table VI. Three valid definitions for the triangle
shown in Figure 15.
Tetrahedron Table
A tetrahedron is determined by its four nodes. In addition,
the permittivity and permeability associated with each
tetrahedron must be stored. In EMAP5 and SIFT5, the matrix
TetNode[TotTetElement][4] stores the node numbers of
each tetrahedron; TetEdge[TotTetElement][6] stores
the edge numbers of each tetrahedron. The matrix
Epson[TotTetElement] stores the complex permittivity
of each tetrahedron. As in the case of the triangle table,
the way to define a tetrahedron is not unique. The sequence
of nodes for a tetrahedron is also determined by the
righthand rule. Edge definitions within a tetrahedron were
discussed in Section II.
PLUS/MINUS TRIANGLE TABLE
When the MoM part of the code is implemented, EMAP5 must
know how triangles are linked to each other. In addition, a
rule defining current direction must be specified. If there
are no junctions, each edge has either one or two
triangles linked to it. If only one triangle
links the edge, the edge is a contour metal edge. All
fields along contour metal edges have to be zero since the
currents have nowhere to go. If there are two triangles
linked to the edge, the triangle with the local direction
coinciding with the global direction will be called the
plus triangle. The triangle with the local direction
opposite to the global direction will be called the minus
triangle. The current is defined to flow from the plus
triangle to the minus triangle. Figure 20 shows an example
demonstrating how plus/minus triangles are determined.
Triangles 1 and 2 are linked by edge
3. The edge's global direction defined by
GlobalEdgeEnds is denoted by the arrow going into
the paper. The normal vectors for both of the
triangles goes inside. If the righthand rule is used,
triangle 1 will be the plus triangle of edge 3,
while triangle 2 will be the minus triangle of edge
3.
Figure 20. Plus/minus triangle definition.
INNER EDGE TABLE
The inner edge table is stored in the array
InnerEdgeStat[TotInnerEdgeNum]. It contains the
edges located within the FEM region. This table can be
generated from the global edge table. It is included in the
input file by SIFT 5 for convenience in EMAP5. All inner
edges will be included in the finite element matrix A.
BOUNDARY EDGE TABLE
The table is stored in the array BoundEdgeStat
[TotBoundEdgeNum]. It stores edge numbers of all
surface edges. All edges in this table will be included in
MoM. Contour edges will not be in this table since the
fields along those edges are zero.
SOURCE INFORMATION
This part of the EMAP5 input file defines how the structure
is excited by a source. EMAP5 supports the following three
kinds of sources:
1. Voltage sources on metal patches 2. Plane wave sources 3. Current sources within the FEM region The symbol 'V', 'P' and 'E' are assigned to each type of sources, respectively. The first line in the mesh file is the source symbol. It should be either 'V', 'P' or 'I'. If the source is 'V', the parameters shown in Table VII should be provided. VSourceEdge[ ] and VSourceMag[ ] are printed one after another. For example, a 'V' source is defined in the EMAP5 input file as follows, V 500 2 23 1.0 45 1.0 The above lines define a 500MHz voltage source with a
magnitude of one volt. The source coincides with the edge
23 and 45.
Table VII. Voltage source definition format.
If the source is an incident plane wave, the parameters shown in Table VIII should be provided. The following lines define a 500MHz plane wave propagating along the +z axis; the E filed is polarized along the +x axis. P 500 90 0 0 0
Table VIII. Plane wave source definition format.
If the source is a 'I' source, the parameters shown in Table IX should be provided. The following lines define a 500MHz source with a magnitude of one Ampere along the edge 10 and 11. I 500.0 2 2 1.0 11 1.0
Table IX. Definition format of a current source
within the FEM region.
JUNCTION TABLE
The parameters shown in Table X are used to define
junctions. Junction[i] defines the junction i+1 as shown in
Table XI.
Table X. Junction definition format.
Table XI. Parameters for the i^{th} junction.
OUTPUT INFORMATIONEMAP5 must know whether users need the default output. In addition, EMAP5 must know how many other output files users want. The parameters shown in Table XII are used to define output requirements. The keyword "output" can be used to define output.
Usually, users are only interested in those edges parallel
to the x, y or z axis. Parameters shown in Table 13 are
used to define a rectangle. Thus, EMAP5 will write fields
along the edges, which are both within the rectangle area
and parallel to the specified axis, to the output
file. Table XII. Output definition format 1.
Table XIII. Output definition format 2.

