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Input Examples
A complete example for a lossless cavity
Code Block |
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ModelInfo: {
File: dds3.ncdf //mesh file. It is the file converted using acdtool
BoundaryCondition: { //specify boundary conditions. The numbers here are sideset in cubit
Magnetic: 1, 2 //reference surfaces 1 and 2 are symmetric planes
Electric: 3 4 //set reference surfaces 3 and 4 to be electric boundary condition
Exterior: 6 //surface group 6 (maybe many surfaces) is metal
}
SurfaceMaterial: { //for each metal (exterior) surface group, list the sigma values
ReferenceNumber: 6
Sigma: 5.8e7
}
}
FiniteElement: {
Order: 2 //set the finite element basis function order to be used.
CurvedSurfaces: on
}
EigenSolver: {
NumEigenvalues: 1 //want to compute 1 mode
FrequencyShift: 10.e9 //the eigenfrequency of the mode should be above 10GHz
}
CheckPoint: {
Action: save
Directory: eigens //eigenvectors are saved out into this directory
}
PostProcess: {
Toggle: off //postprocess switch
ModeFile: dds //The prefix of the mode filename.
}
Log: thisrun.log //If you want more printout logged into the file
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...
Code Block |
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acdtool postprocess eigentomode eigens
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Code Block |
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ModelInfo: {
File: ./pillbox.ncdf
BoundaryCondition: {
Electric: 1,2,3,4
Exterior: 6
}
Material : {
Attribute: 1
Epsilon: 1.0
Mu: 1.0
}
Material : {
Attribute: 2
Epsilon: 1.0
Mu: 1.0
EpsilonImag: -0.2 //lossy material
}
}
FiniteElement: {
Order: 1
Curved Surfaces: off
}
PostProcess: {
Toggle: off
ModeFile: mode
SymmetryFactor: 2
}
EigenSolver: {
NumEigenvalues: 2
FrequencyShift: 5e9
}
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A complete example with
...
periodic boundary conditions
Code Block |
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ModelInfo: {
File: cell1fourthc026ds-pbc.ncdf
BoundaryCondition: {
Magnetic: 1, 2,3,4
Exterior: 6
Periodic_M: 3 //master surface
WaveguidePeriodic_S: 7 4 //forslave eachsurface, numberthe appearedmesh here,should itbe shouldexactly havesame atas leastthose oneon Portthe containermaster later.surface
Exterior: }6
}
FiniteElementTheta: {
-150 Order: //phase
}
}
FiniteElement: {
Order: 2
CurvedSurfaces: 1on
ScalarPotential: 1 Curved Surfaces: on
//use A-V formulation
}
PostProcess:
{
Toggle: on
ModeFile: testmode
}
SymmetryFactor:
8.
}
EigenSolver: {
NumEigenvalues: 1
FrequencyShift: 10e9
}
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A complete example with waveguide loaded cavity
Code Block |
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9.e9
}
CheckPointModelInfo: {
ActionFile: savecell1fourth.ncdf
DirectoryBoundaryCondition: eigens{
}
PortMagnetic: {1,2,3,4
Exterior: 6
ReferenceNumber: 7 //this number should match surface groups in waveguide boundary condition.
Origin: 0.0, 0.0415, 0.0 //the origin of the 2D port in the 3D coordinate system
XDirection: 1.0, 0.0, 0.0 //the x axis of the 2D port in the 3D coordinate system
YDirection: 0.0, 0.0, -1.0 //the y axis of the 2D port in the 3D coordinate system
ESolverWaveguide: 7 //for each number appeared here, it should have at least one Port container later. Absorbing and Waveguide have the same effects. Omega3P internally will figure out which BC to use.
}
}
FiniteElement: {
Order: 1
Curved Surfaces: on
}
PostProcess: {
Toggle: on
ModeFile: test
}
EigenSolver: {
NumEigenvalues: 1
FrequencyShift: 9.e9
}
CheckPoint: {
Action: save
Directory: eigens
}
TypePort: Analytic{
ReferenceNumber: 7 //analyticthis expressionnumber isshould usedmatch
surface groups in waveguide boundary condition.
ModeOrigin: {
0.0, 0.0415, 0.0 //the origin of the 2D port in the 3D coordinate system
WaveguideType: Rectangular XDirection: //it is a rectangular waveguide
1.0, 0.0, 0.0 //the x axis of the 2D port in the 3D coordinate system
ModeTypeYDirection: TE 1 0 0.0, 0.0, -1.0 //the y axis of the 2D port in the 3D coordinate system
//load the TE10 mode
ESolver: {
Type: Analytic A: 0.028499 //analytic expression is used
//dimension ofMode: the{
waveguide in x
WaveguideType: Rectangular B: 0.0134053 //it is a rectangular waveguide
//dimension of the waveguideModeType: inTE y
1 0 }
//load the TE10 mode
}
}
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Load TEM mode in a coax waveguide
Code Block |
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Port: {
ReferenceNumber: 2
A: 0.028499 Origin: 0.0, 0.0, 0.011
ESolver: {
//dimension of the waveguide in Type: Analyticx
Mode: {
B: 0.0134053 WaveguideType: Coax
//dimension of the waveguide in y
ModeType: TEM
}
}
}
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Load TEM mode in a coax waveguide
Code Block |
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Port: {
A: 0.0011 //smaller radiusReferenceNumber: 2
Origin: 0.0, 0.0, 0.011
BESolver: 0.0033 //larger radius
{
Type: Analytic
Mode: }
{
WaveguideType: }Coax
}
ModeType: TEM
A: 0.0011 //smaller radius
B: 0.0033 //larger radius
}
}
}
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Load TE11 mode in a circular waveguide
Code Block |
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Port: {
ReferenceNumber: 2
Origin: 0.0, 0.0, 0.1
XDirection: 1.0, 0.0, 0.0
YDirection: 0.0, 1.0, 0.0
ESolver: {
Type: Analytic
Mode: {
Waveguide type: Circular
Mode type: TE 1 1
A: 0.03
}
}
}
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Load two TE modes in the same rectangular waveguide
Code Block |
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Port: {
Reference number: 9 // FPC
Origin: 0.0, 0.198907, -0.4479152585
XDirection: -1.0, 0.0, 0.0
YDirection: 0.0, 0.0, 1.0
ESolver: {
Type: Analytic
Mode: {
WaveguideType: Rectangular
ModeType: TE 1 1
A: 0.1348935946
B: 0.024973714999999970
}
}
}
Port: {
Reference number: 9 // FPC
Origin: 0.0, 0.198907, -0.4479152585
XDirection: -1.0, 0.0, 0.0
YDirection: 0.0, 0.0, 1.0
ESolver: {
Type: Analytic
Mode: {
WaveguideType: Rectangular
ModeType: TE 2 0
A: 0.1348935946
B: 0.024973714999999970
}
}
}
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Make a non-planar surface absorbing boundary
Code Block |
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Port: {
ReferenceNumber: 5 //reference surface ID
Origin: 0.0, 0.0, 0.0 //not used
XDirection: 1.0, 0.0, 0.0 //not used
YDirection: 0.0, 1.0, 0.0 //not used
ESolver: {
Type: Analytic
Mode:{
Mode number: 1
Waveguide type: ABC
Mode type: ABC
}
}
}
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LinearSolver options in EigenSolver container
- The first option is that user does not provide anything. The EigenSolver container in the input file looks like:
Code Block |
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EigenSolver: {
NumEigenvalues: 1
FrequencyShift: 10.e9
Tolerance: 1.e-8
}
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In this case, Omega3P will use the default option for linear solver for solving shifted linear systems
- The second option is to use float version of the sparse direct solver.
Code Block |
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EigenSolver: {
NumEigenvalues: 1
FrequencyShift: 10.e9
Preconditioner: MUMPSFLOAT //use the float version. memory usage reduced into half.
}
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- The third option is to use Krylov subspace method with different preconditioner.
Code Block |
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EigenSolver: {
NumEigenvalues: 1
FrequencyShift: 10.e9
Preconditioner: MP //this use p-version of multilevel preconditioner.
}
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The code will choose either CG (real matrices) or GMRES (complex matrices) and the p-version
of multilevel precondtioner as the solver for shifted linear systems.
- The fourth option is to use out-of-core sparse direct solver (an experimental feature).
Code Block |
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EigenSolver: {
NumEigenvalues: 1
FrequencyShift: 10.e9
Memory: 1000 //if the memory usage of the matrix factor in any process is larger than 1000MBytes,
//switch to use out-of-core solver.
}
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FAQ
How to calculate Wallloss Quality Factor?
There are two ways to do so. Each way has its advantage and disadvantage.
- Inside ModelInfo.BoundaryCondition define a set of boundary surfaces as Exterior.
For each of the boundary surfaces, have a corresponding SurfaceMaterial container inside ModelInfo.
For example: Code Block |
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ModelInfo: {
File: .dds3.ncdf
BoundaryCondition: {
Magnetic: 1, 2, 3, 4
Exterior: 6 // sideset 6 is defined as Exterior BC.
}
SurfaceMaterial: { // have a separate for each number in Exterior BC
ReferenceNumber: 6 //the corresponding sideset in Exterior BC
Sigma: 5.8e7 //electrical conductivity of the material
}
}
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After that, make sure you toggle the PostProcess on. Code Block |
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PostProcess: {
Toggle: on // this should be on for computing wallloss Q
ModeFile: ./dds
}
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After you run omega3p with the input file, you will get a file called "output" under the same directory. Inside the file, it has a summary of results such as: Code Block |
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Mode : {
TotalEnergy : 4.4270939088102e-12
QualityFactor : 6478.5096350252
File : ./dds.l0.1.144469E+10.m0
PowerLoss : 4.9139118623939e-05
Frequency : 11444685657.626
}
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The number after QualityFactor is the one you are looking for. This method uses perturbation theory and has advantage that it is very simple. The computation associated with it is minimal. - Inside ModelInfo.BoundaryCondition, define the set of surfaces as Impedance (instead of Exterior in method 1).
Set the HFormulation to be 1 (this is very important). Also, have a set of corresponding SurfaceMaterials inside ModelInfo as those in method 1. For example: Code Block |
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ModelInfo: {
File: dds3.ncdf
BoundaryCondition: {
HFormulation: 1
Magnetic: 1, 2, 3, 4
Impedance: 6
}
SurfaceMaterial: {
ReferenceNumber: 6
Sigma: 5.8e7
}
}
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After you run omega3p with the input, in the output file, you will see Code Block |
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Mode = {
TotalEnergy = { 6.2827077634198e-07, 0 },
ExternalQ = 6579.1486638005,
QualityFactor = inf,
File = './dds.l0.R1.144619E+10I8.698837E+05.m0',
PowerLoss = 0,
Frequency = { 11446188331.641, 869883.69746227 }
}
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The number after ExternalQ is the wall loss Q you are looking for. During the omega3p run, it should also print out the Q information such as Code Block |
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COMMIT MODE: 0 FREQ = (11446188331.64141,869883.6974622669) k = (239.8943683519209,0.01823141417003215) Q = 6579.148663800495
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Note that this method set an impedance boundary condition on those surfaces and make the eigenvalue problem complex and nonlinear. It takes more time and memory to solve the problem. But the field will be in the right phase (even close to the boundary surfaces).
Both methods should give you converged Q results if mesh is dense enough.