Introduction to High Frequency Structure Simulator

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Introduction to High Frequency Structure Simulator

• Pengcheng Jia

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Background

• Introduced from 90s
• Simulation tool for complex 3 D geometries
• Using Finite Element Method
• Adaptive Mesh generation refinement
• 2 Main VendorsAgilent Ansoft
• Merger from May 1
• Transfer to Ansoft HFSS after Nov. 1, 2001

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Requirement Resources

• HFSS consume tremendous memory if fine result is
  needed
• 300M Memory and 400M processor is recommended
• Floating License Key within ECEWIN2K subnet
• Remote access to new Scully which has 1 G
  RAMBUS400 Memory and 1.7G P4 processor

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Agilent HFSS
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Ansoft HFSS
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Features(1)

• Computes s-parameters and full-wave fields for
  arbitrarily-shaped 3D passive structures
• Powerful drawing capabilities to simplify design
  entry
• Field solving engine with accuracy-driven
  adaptive solutions
• Powerful post-processor for unprecedented insight
  into electrical performance

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Features(2)

• Advanced materials
• Model Library-including spiral inductors
• Model half, quarter, or octet symmetry
• Calculate far-field patterns
• Wideband fast frequency sweep
• Create parameterized cross section models- 2D
  models

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Applications

• Antennas
• Microwave transitions
• Waveguide components
• RF filters
• Three-dimensional discontinuities
• Passive circuit elements

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Procedure to simulate

1. Open or Make new project
2. Draw objects
3. Assign material property
4. Define boundary conditions
5. Solve
6. Display result

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New project
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Project Preferences
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Drawing basics
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Drawing Lines 2 D objects
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Drawing 3 D objects
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Object Library
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Editing Objects
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Materials
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Metal Resistor
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Boundaries
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Boundary Conditions
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Add A Boundary
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Display Boundary
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Calibrating Ports
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Solve
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Frequency Meshing
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Displaying Results
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S Matrix
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Plot Field
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Result Comparison

• ?r8.5 Hsub625 um W150um G75 um

---Theoretical Equation
_at_10G Theoretical HFSS
L100 um 0.04 nH 0.05 nH
L300 um 0.12 nH 0.13 nH
L600 um 0.24 nH 0.24 nH
L800 um 0.33 nH 0.31 nH
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Finite Element Method
Tetrahedron
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Impedance Concept

• Zpi, Zpv Zvi
• Microstrips use Zpi impedance
• Slot-type (CPW) use Zpv impedance
• TEM waves use Zvi impedance

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Projects with HFSS

• Microstrip Line to Waveguide Transition

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EM Field of the transition
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Waveguide Combiner System
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Slotline Antenna
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Bonding Wire Discontinuity
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Packaging for CPW Lines
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Field Plot
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Useful links

• http//www.ansoft.com
• http//dutettq.et.tudelft.nl/hfss/welcome.html
• http//wwwinfo.cern.ch/ce/ae/Maxwell/index.html
• Documents for HP HFSS is in Scully
• c/Otherprg/hfss/doc

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References

• HP High-Frequency Structure Simulator Users
  Reference
• HP High-Frequency Structure Simulator Tutorial