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Fast and Accurate Simulation of
Installed Antenna Performance
Matt Miller
President
September 17, 2014
Installed Antenna Performance Problem
• Antennas interact with installed platform – Multipath, diffraction, creeping waves, etc.
• Need to accurately characterize antenna performance – Communications links, radar, cosite, etc.
• Measurement vs. Simulation – Measurement is expensive, time consuming and difficult
– Simulation is affordable, fast, and flexible
Savant Overview
• Advanced installed antenna performance simulation
software
– Fast and accurate prediction of installed patterns, near-
fields, and antenna coupling
Savant Advantages
• Extremely Fast – Multicore, GPU and MPI
• Low Memory Requirements – Most jobs require less than 8 GB of RAM
• Accurate – Physics models not found in other SBR tools
• Intuitive – Powerful GUI with thorough Help/Tutorials
• Workflow – Antenna design tools, CEM tools and Matlab
• Expertise – The most experienced SBR development
team anywhere
GPU and MPI Examples
• Monopole on 737-800 – Compute installed pattern
• 40,000 angular samples
• 3 to 4 GHz, 40 MHz steps
• 747,820 rays hit CAD
– Using single CPU core: 12 hrs, 18 min
– Using four CPU cores: 3 hrs, 12 min (4x)
– Using 1 CPU core, 1 GPU: 10.7 min (> 70x)
– Using 4 CPU cores, 2 GPU: 6.2 min (>118x)
• 94 GHz Antenna on UH-60 – Compute installed pattern
– Using 1 Node, 6 cores, 2 GPUs
• 720 seconds (12 minutes)
– Using 5 Nodes, 30 CPU cores, 10 GPUs
• 143 seconds (5x)
– Computer hardware costs $20K
6,170 λ
477λ x 527λ x 167λ
Methodology: SBR+
• What is SBR ?
– SBR = Shooting and Bouncing Rays
• Asymptotic technique for electrically large platforms
• Complimentary capability to full-wave solvers
• Extends physical optics (PO) to multiple bounces with GO ray tracing
• SBR+ ?
– Build on SBR with additional physics
• Physical Theory of Diffraction (PTD)
• Creeping Wave
• Uniform Theory of Diffraction (UTD) Rays
– Driving development philosophy
• Use full array of GTD/UTD methods to “paint”
currents on platform body
• All models/mechanisms should work together
SBR+ Algorithms
• SBR Rays
– Launch rays from antenna
– “Paint” PO currents on surfaces
• Creeping Wave Rays
– Trace rays along surfaces
– Deposit currents
SBR+ Algorithms
• SBR Rays
– Launch rays from antenna
– “Paint” PO currents on surfaces
• Creeping Wave Rays
– Trace rays along surfaces
– Deposit currents
• PTD
– Correct PO currents at edges
SBR+ Algorithms
• SBR Rays
– Launch rays from antenna
– “Paint” PO currents on surfaces
• Creeping Wave Rays
– Trace rays along surfaces
– Deposit currents
• PTD
– Correct PO currents at edges
• UTD Rays
– Launch edge diffraction rays along edges
– Paint currents in shadow regions
Accuracy: Creeping Wave
Savant (SBR+CW)
MoM
Creeping Wave Is Very Important For This
Problem!
Savant is the only SBR tool with this
capability
Antenna Models
• Free-space antenna model required for Savant
– Far-field radiation patterns
– Current sources
• Built in parametric models
– Dipoles, monopoles, loops, slots
– Pyramidal and Conical horns
– Parametric Beam
• Array Design Tool
– Linear, Rectangular, Elliptical & By File
– Weighting and phasing of elements
– Far-field or current sources for elements
• Import Full-Wave 3D Antenna Models
– HFSS
– CST
– FEKO
– WIPL-D
V-22 S-Band Antenna Example
S-Band Blade Antenna
2.3 GHz
1,620 simulations to
capture moving blades and
engine assemblies
6 hours to compute all
jobs on laptop 133λ x 200λ x 51λ
HFSS/Savant Integration Example
Substrate
h = 1.575 mm
εr = 2.2
• Run HFSS to obtain,
– Near-field data
– Far-field data
• Run Savant with HFSS current source model
• Compare far-field results
Savant
HFSS
HFSS CSRC Model
272 sources
5.7 seconds on laptop computer
HFSS/Savant Integration Example
Savant Runtime: 16 minutes on laptop with quad core CPU and NVIDIA Quadro
K2000M GPU
Connected Vehicle Scenario #1
• Compute installed pattern for 5.9 GHz antenna as a large
delivery truck passes the sedan
• Pattern computed every 0.1 meter as delivery truck
approaches sedan from behind and passes
251 simulations
12.5 hours to run all jobs
on laptop computer
180 seconds per simulation
651λ x 180λ x 74λ
Connected Vehicle Scenario #2
• Compute coupling between two 5.9 GHz antennas
5.9 GHz Transmitter
and Antenna
Receiver
and Antenna 287 simulations
12.1 hours to run all jobs
on laptop computer
152 seconds per simulation
651λ x 180λ x 74λ
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