Computer Modeling of Modern Antenna Arrays

Computer Modeling of Modern Antenna ArraysMarinos N. Vouvakis

Obtain Transfer Fn of Building Block (FETI)

Problem Partitioning in Domains*

Adaptive Mesh Refinement on

Building Blocks

Construct Domains

Using Building Blocks*

Connect Domains using “cement”

technique & Outer Loop DDM Iteration

Extract Engineering Info. Antenna Pattern, Impedance,

Q Factors, etc

Recover Fields from Reduced Surface Unknowns for Each

Domain

*Domain is a translation invariant instance of a Building

Block.

Analysis OverviewHigher Order FEM–Tree-Cotree–pMUS–hAMR–DD–Cement–FETI

x

y

zθ=30º

φ=90º

d=7.9λ

300×300

Single Polarized

16×16 ×2

Finite Arrays of Vivaldi Tapered Slot AntennasSimulation over 900 million unknowns of very complicated geometry

HFSS infinite array prediction

DD-FEM prediction

1 billion FEM unknowns on a PC in 1 day.

Dual Polarized

Good agreement with commercial simulators

Scan

dire

ctio

n

G0=23.31dBi (Simulated)G0=23.44dBi (Measured)

Scan dirzection

24×12 RADAR Sub-array ModuleDomain Decomposition FEM vs. Measurements

Good agreement with measurements (impedance too)

≈17dB

Scattering of Patch Arrays on Finite DielectricParametric Studies

≈22dB≈12dB

Geometry

Effect of Array Size Effect of Array Shape

Effect of Element Loading

0° scan

x

y

z

Active Reflection Coeff.Near & Far Fields

x

y

z

Finite Patch Arrays on Truncated CylindersDD-FEM for Curved Structures (Rotational Symmetry)

60° H-scan

x

y

z

x

y

z

Planar vs. Cylindrical Finite Patch ArraysFor Small Radius Radiation by Planar and Cylindrical Arrays is Different

Finite Planar Array Finite Cylindrical Array

xy

xz

(TTVG-800)

(TTVG-800)

Active Reflection Coeff.

Near & Far Fields

Magnitude Phase

Geometry.

Finite Arrays of Ferrite Loaded CBS ArraysDD-FEM for anisotropic non-reciprocal materials

Arrays involving complex material simulated in PCs within few hours

−15

−10

−5

0

5

10

0

30

60

90

120

150

180180

150

120

90

60

30

Top View —1.5λ away

Back View —1.5λ away

PEC

Ground Plane

AM

C G

roun

d Pl

ane

Back View —1.5λ away

Top View —1.5λ away

PEC Ground PlaneAMC Ground Plane

Monopole Radiation over EBGSimulation of 39 million unknowns

Teflon Lens

Split Ring LensNegative Refraction Lens

Geometry (Top View)

Metamaterial Plano-concave Lens3D simulation of 50 million unknowns, Very challenging geometry

Memory=4.5 GbElectric size ≈ 60λ×12λ×8λInitial h=λ/6h-AMR steps 3Iterations=39#Unkowns=3,838,554Solution Time- 7.6 hours

E

E

Scattering by BattleshipDomain Decomposition FEM-BEM Hybrid