Simulation/Optimization
Team:
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
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
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
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 highdensity 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
Performance capability modeling for 60GHz cavity filters
 Variables:
 Wc = the cavity width
 Ws = the slot width
 Wf = the feedline width
 Responses:
 f_{res} = resonant frequency
 IL = insertion loss
 RL = return loss
 BW = bandwidth
Monte Carlo Analysis:
Mode decomposition in Inverted Embedded Microstrip
 Electric fields hit surface of silicon substrate rather than air
 Silicon: σ = 5S/m; ε_{r} = 11.9
 Polyimide: σ = 3.4e10S/m; ε_{r} = 3.12
Conventional Microstrip quasiTEM mode
QuasiMicrostrip quasiTEM mode
QuasiParallel plate mode
QuasiStripline mode