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6. Electromagnetics Enhancements

6. Electromagnetics Enhancements. Electromagnetics Enhancements. Emag focus in ANSYS 5.7 is on high-frequency electromagnetics (discussed next). Other Emag enhancements: LMATRIX (inductance calculation) improvements

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6. Electromagnetics Enhancements

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  1. 6. Electromagnetics Enhancements

  2. Electromagnetics 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 001419 15 Aug 2000 6-2

  3. … 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 001419 15 Aug 2000 6-3

  4. High 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 001419 15 Aug 2000 6-4

  5. New/enhanced Harmonic analysis Existing Modal analysis CAD import Boundary conditions HF Elements materials HF Postprocessing Excitations … High Frequency Electromagnetics Overview (cont'd) Major components of a HF FEA model Training Manual 001419 15 Aug 2000 6-5

  6. … 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 001419 15 Aug 2000 6-6

  7. HF Electromagnetics - New BC'sPML 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 001419 15 Aug 2000 6-7

  8. PML Surrounding field HF Device HF 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 Schematic of cross section of a 3D PML region Training Manual 001419 15 Aug 2000 6-8

  9. HF 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. PML2 PML2 ESYS2 ESYS2 PML1 PML1 Schematic of 1D PML layers ESYS1 ESYS1 ESYS3 PML3 PML3 Training Manual 001419 15 Aug 2000 6-9

  10. conductor HF Electromagnetics - New BC'sImpedance • 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 air-dielectric Interface surface of non-perfect conductor dielectric non-perfect conductor far-field boundary air PEC with dielectric coating Training Manual 001419 15 Aug 2000 6-10

  11. y y y y y x x x x x z z z HF Electromagnetics - New ExcitationsWaveguide 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. new Rectangular Waveguide Parallel-Plate Waveguide Circular Waveguide Coax Waveguide Training Manual 001419 15 Aug 2000 6-11

  12. HF Electromagnetics - New Excitations...Waveguide Ports • Higher-order modes are now available at 5.7: Training Manual 001419 15 Aug 2000 6-12

  13. HF 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 001419 15 Aug 2000 6-13

  14. port SEXT IMPD port HF Electromagnetics - New Excitations...Waveguide Ports • Schematics of four Portbc options for waveguides in HFPORT command PML2 PML1 incident wave SOFT HARD incident wave incident wave incident wave reflection wave reflection wave Training Manual 001419 15 Aug 2000 6-14

  15. HF Electromagnetics - New ExcitationsPlane 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 001419 15 Aug 2000 6-15

  16. HF Electromagnetics - New ExcitationsSource 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 001419 15 Aug 2000 6-16

  17. HF ElectromagneticsElement 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 001419 15 Aug 2000 6-17

  18. HF 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 001419 15 Aug 2000 6-18

  19. HF ElectromagneticsSolution 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 001419 15 Aug 2000 6-19

  20. 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 HF Electromagnetics… Solution and Postprocessing Training Manual 001419 15 Aug 2000 6-20

  21. HF 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) Training Manual 001419 15 Aug 2000 6-21

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