6. electromagnetics enhancements. training manual 001419 15 aug 2000 6-2 electromagnetics...
TRANSCRIPT
6. Electromagnetics Enhancements
Training Manual 00141915 Aug 2000
6-2
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7Electromagnetics Enhancements
• Emag focus in ANSYS 5.7 is on high-frequency electromagnetics (discussed next).
• Other Emag enhancements:
– LMATRIX (inductance calculation) improvements• Output array contains the NxN inductance matrix (as before)
and a new N+1th column containing flux linkage values, with the I th row corresponding to the I th coil.
– SENERGY (magnetic energy calculation) is more robust, accurate, and faster.
Training Manual 00141915 Aug 2000
6-3
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7… Electromagnetics Enhancements
• Other Emag enhancements (cont'd):
– New diode element, CIRCU125• To simulate a common or Zener diode.
• Can interface with circuit element CIRCU124, transducer element TRANS126, and mechanical elements MASS21, COMBIN14, and COMBIN39 for coupled-field analyses.
• Can be defined using the circuit builder.
CIRCU125
Training Manual 00141915 Aug 2000
6-4
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7High Frequency Electromagnetics
Overview
• In ANSYS, HF Electromagnetics is used to simulate the full wave electromagnetic phenomena.
– RF/microwave problems (interior wave propagation)
– Radiation and scattering problems (exterior wave propagation)
• Available in ANSYS/Multiphysics and ANSYS/Emag HF products.
• HF solution is in the frequency domain.
• No limit on the highest frequency allowed.
Training Manual 00141915 Aug 2000
6-5
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7
… High Frequency Electromagnetics
Overview (cont'd)
Major components of a HF FEA model
HF PostprocessingExcitations
materials
Boundaryconditions
Modal analysis
Harmonic analysis
CAD import
New/enhancedExisting
HF Elements
Training Manual 00141915 Aug 2000
6-6
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7… High Frequency Electromagnetics
Overview (cont'd)
• ANSYS 5.7 takes a major leap in HF simulation capabilities with several new features and enhancements:
– New boundary conditions• PML (perfectly matched layer), impedance
– New excitations• Waveguide ports; plane wave; surface magnetic field, surface
electric field, and current density excitations
– Elements• New HF118 element, enhancements to HF119 & HF120
– Solvers and postprocessing
Training Manual 00141915 Aug 2000
6-7
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New BC's
PML
Perfectly Matched Layer (PML)
• Absorbing layers of elements used for the truncation of the HF FEA domain.
• Reduce the FEA domain significantly by replacing the outer computation domain (infinite) with an absorbing layers.
• Required in many real world applications:
– Exterior phenomena, e.g, antenna and EMC/EMI problems.
– Interior phenomena, e.g, waveguides and transmission lines.
Training Manual 00141915 Aug 2000
6-8
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New BC's
… PML
• PML region is simply a layer (or layers) of elements placed at the boundary of the field domain.
• Elements used are 119 and 120 with KEYOPT(4) = 1. For example: ET,2,HF120,,,,1
– Extend the material properties in the field region into PML
– PML supports symmetry boundary conditions
PML
Surrounding field
HF Device Schematic of cross sectionof a 3D PML region
Training Manual 00141915 Aug 2000
6-9
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New BC's
… PML
• Recommendations:– PML boundary edges should be parallel to global Cartesian or Cartesian
ESYS.
– Thickness of PML region > 0.25*wavelength.
– Allow at least 4-5 layers of elements in surrounding field as buffer zone between device and PML.
– Four elements through the thickness of PML region for - 50 Db attenuation. More attenuation can be obtained by adding more PML layers.
PML1
PML2
PML3ESYS1
ESYS2
ESYS3
Schematic of1D PML layers
PML1
PML2
PML3ESYS1
ESYS2
Training Manual 00141915 Aug 2000
6-10
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New BC's
Impedance
• Four types of impedance BC's are now available:
– Far-field radiation boundary
– Air-dielectric boundary
– PEC (perfect electric conductor) surface with dielectric coating
– Non-PEC surface
• Apply using SF family of commands
dielectric
air-dielectricInterface
air
far-field boundary
PEC with dielectric coating
non-perfect conductor
surface of non-perfectconductor
conductor
Training Manual 00141915 Aug 2000
6-11
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New Excitations
Waveguide Ports
• New parallel-plate waveguide
– Can be used to simulate problems like micro-strip.
• All four types of waveguides
– Z axis can be in either the wave propagation direction or the opposite direction. X-axis must be parallel to width of port.
– Origin for rectangular waveguide is at center, different from 5.6.
x
y
zRectangular Waveguide
Parallel-PlateWaveguide
CircularWaveguide
Coax Waveguide
new
x
y
x
y
x
y
z
x
y
z
Training Manual 00141915 Aug 2000
6-12
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New Excitations
...Waveguide Ports
• Higher-order modes are now available at 5.7:
COAX RECT CIRC PARA
TEM TEM
TEmn TEmn TE0n
TMmn TMmn TM0n
Training Manual 00141915 Aug 2000
6-13
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New Excitations
...Waveguide Ports
• HFPORT,Portnum,Porttype,Local,Mode,Portbc,VAL1,VAL2,VAL3,VAL4,VAL5
• New HFPORT command replaces PORTOPT.
• Port boundary conditions by Portbc in HFPORT:
– IMPD Matching the impedance of the single mode.
– SEXT Terminating the port w/ PML layers. An invisible port to extract S-parameters.
– SOFT Equivalent current excitation. Allow multiple ports & multiple modes. Can extract S-parameter.
– HARD Fixed electromagnetic field at port.
Training Manual 00141915 Aug 2000
6-14
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New Excitations
...Waveguide Ports
• Schematics of four Portbc options for waveguides in HFPORT command
portSEXTport IMPD
HARDincident waveincident waveincident wave
reflection wave reflection wave
SOFT
incident wave
PML2
PML1
Training Manual 00141915 Aug 2000
6-15
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New Excitations
Plane Wave
• New PLWAVE command replaces PLANEWAVE:
– PLWAVE, EX, EY, EZ, AngX, AngZ• EX, EY and EZ are the electric field amplitudes in X, Y and Z
directions.
• AngX and AngZ are the angles of the wave to X-axis and Z-axis.
– Used for scattering analysis in EMC/EMI analysis
Training Manual 00141915 Aug 2000
6-16
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics - New Excitations
Source Terms
• You can now specify the following excitation sources (using the BF family of commands):
– Magnetic field (H) at a surface.
– Electric field (EF) at a surface.
– Current density (JS) at a point, line, surface, or volume.
Training Manual 00141915 Aug 2000
6-17
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics
Element Enhancements
• New 2.5-D, 8-node HF118 element
– Extract eigenvalues of guided wave structures (waveguides or transmission lines).
– Applicable for modal analyses (Block Lanczos).
– Quadrilateral or triangular shapes.
– Both 1st order and 2nd order available.
– To calculate cutoff frequencies and propagating constants used together with HFEIGOPT.
Training Manual 00141915 Aug 2000
6-18
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics
… Element Enhancements
• HF119 (10-node tet) gets new 2nd-order option
– Applicable to both modal and full harmonic analyses
– Keyopt(1) = 2
– Better accuracy compared with 1st order element, especially for complex geometry
• HF120 (20-node brick) gets improved 2nd-order option
– DOFs from 36/element to 54/element
– Complete vector basis functions
– Better accuracy for higher-order modes
Training Manual 00141915 Aug 2000
6-19
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics
Solution and Postprocessing
• Sparse solver is now the default (not frontal).
– ICCG and FRONTAL also available as before
• Choosing analysis types
– Harmonic analysis (Antype, harmic)HFSCAT,SCAT must be specified for RCS calculation
– Modal analysis (Antype,modal) 3D or 2D modal analysis
Training Manual 00141915 Aug 2000
6-20
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics
… Solution and Postprocessing
• New commands to review far-field results:
– PLHFFAR to display the electromagnetic far field, radar cross-section (RCS), and antenna pattern (PATT)
– PRHFFAR for listings
RCS of a metal plate with incident plane wave
Training Manual 00141915 Aug 2000
6-21
NEW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7N
EW
FEA
TU
RES 5
.7HF Electromagnetics
… Solution and Postprocessing
• New HFNEAR command to calculate near-field results (EF & H).
– Options to calculate at a specified point or along a path.
• New PRHFFAR calculates/prints far field beyond FEA domain.
• Other:
– HFSYM to set symmetry planes for postprocessing calculations in near and far field
– Current density can be shown graphically
– Calculated parameters:• SPARM: magnitude and phase angle of S-parameter (both
single and multiple ports)