Daniela Staiculescu, Amil Haque, Amir Dindar, Brian McGarvey, Lara Martin

Hybrid FDTD method

Statement of Problem or Challenges:

  • The equations for the correction factor calculation are shown.
    • Integral approximations for the numerators are calculated using fine static grid
    • Approximations for denominators are calculated using coarse dynamic grid
  • Correction factors are applied in areas of large field variation—see figure
  • The static and dynamic grids are shown.
  • The red dot is the position of the field value used to calculate the denominator of the correction factor expression

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MRTD Subcell Modeling

1D MRTD cell utilizing Haar wavelets (pulses) intersected by PEC (perfect electrical conductor)

Coefficients of wavelets intersecting the PEC are zeroed

Metals intersecting a cell can be modeled with this technique

One example of subcell areas is the via array in the above resonator

2D cell intersected by PEC

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DOE, RSM & POA Optimization Techniques

  • High level of compactness and integration requires more sophisticated design tools
  • Need for
    • thorough understanding of factor effects
    • how factors interact
    • which factors are not significant
  • Hybrid method includes statistical and electromagnetic tools
  • Correction factors are applied in areas of large field variation—see figure
  • Statistical tools include Design of Experiments (DOE), Response Surface Methods (RSM) and Path of Ascent (POA)
  • POA:
  • Applied to determine a path for further optimization of the figures of merit
  • Run simulations until the optimum or a design rule limitation is reached
  • Optimum POA point used to identify another design space; another full factorial DOE with center points is performed
  • Process is complete when the performance goal or optimum performance is achieved

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Hybrid simultaneous electrical/mecahnical optimization of composite smart structures

Antenna structure is sandwiched between two relatively dense and stiff facesheets bonded to either side of a high-density core

  • Variables:
    • h = the honeycomb thickness
    • t = the facesheet thickness
  • Responses:
    • G = antenna gain at resonant frequency (12.2 GHz)
    • D = mechanical deflection
  • Optimization values:
    • G = 12 dB and D = 1.36 mm
  • Optimal inputs:
    • t = 1.5 mm and h = 8.64 mm

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Performance capability modeling for 60GHz cavity filters

  • Variables:
    • Wc = the cavity width
    • Ws = the slot width
    • Wf = the feedline width
  • Responses:
    • fres = resonant frequency
    • IL = insertion loss
    • RL = return loss
    • BW = bandwidth

Monte Carlo Analysis:

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Mode decomposition in Inverted Embedded Microstrip

  • Electric fields hit surface of silicon substrate rather than air
  • Silicon: σ = 5S/m; εr = 11.9
  • Polyimide: σ = 3.4e-10S/m; εr = 3.12

Conventional Microstrip quasi-TEM mode

Quasi-Microstrip quasi-TEM mode

Quasi-Parallel plate mode

Quasi-Stripline mode

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