Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

1UIUCUH

Initial Problems Pieces

Develop Understanding of Coupling

Early Catalog of Expected Waveforms at Circuit Terminals

Incorporate into Topological Models

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

2UIUCUH

Short-Term ProblemsWires and Slots

• Obtain useful information quickly – 10 months

• Develop understanding of coupling mechanisms

• Assess influence of wires and slots on waveforms

• Catalog waveforms that can be expected at a pin of a digital system

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

3UIUCUH

Wire Excited through Slot

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

4UIUCUH

Wire through Hole

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

5UIUCUH

Wires Coupled through Slot

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

6UIUCUH

Slot Excited Wire between Plates

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

7UIUCUH

Wire through Holes in Parallel Plates

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

8UIUCUH

Short-Term ProblemsCascaded Coaxial Cavities

• Obtain useful information quickly – 12 months

• Develop understanding of coupling mechanisms involving cascaded cavities

• Assess influence of cascaded cavities on waveforms

• Catalog waveforms that can be expected at the terminus of a chain of cascaded cavities

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

9UIUCUH

Effects of Propagation Path on Transient Signal – Cascaded Cavities

Coax Terminationw/ Load

Casaded CoaxialCavities

Transient Signal Excitation

PlanarDiscontinuities

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

10UIUCUH

Effects of Propagation Path on Transient Signal – Cascaded Cavities with Load

LZ

Load Im pedance

C asaded C oaxia lC avities

T ransient S ignal Excitation

P lanarD iscontinuities

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

11UIUCUH

Wire in Cascaded Cavities Loaded by Disk

C oax Term inationw/ Load

C asaded C oaxia lC avities

T ransient S ignal Excitation

P lanarD iscontinuity R esistive D isk

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

12UIUCUH

Open Wire in Cascaded Cavities Loaded by Disk

R esistive D isk

C asaded Coaxia lC avities

T ransient S ignal Excitation

P lanarD iscontinuity

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

13UIUCUH

Coupling into Cascaded Cavities

LZ

PEC Screen

Load Im pedance

W ireSm all Entry H ole

C asaded C oaxia lC avities

T ransient S ignal Excitation

P lanarD iscontinuities

Sm all H ole

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

14UIUCUH

Coupling into Cascaded Cavities

LZ

PEC Screen

Load Im pedance

Thin-W ire Antenna

Sm all Aperture

C asaded C oaxia lC avities

T ransient S ignal Excitation

P lanarD iscontinuities

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

15UIUCUH

Coupling into Cascaded Cavities

LZ

PEC Screen

Load Im pedance

Thin-W ire Antenna

Sm all Aperture

C asaded C oaxia lC avities

T ransient S ignal Excitation

P lanarD iscontinuities

,qJ

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

16UIUCUH

Short-Term ProblemsFast Time-Domain Methods

Development

• Fast time-domain integral equation methods for inhomogeneous material regions

• Hybrid circuit theory -- TDIE analysis

• TDIE analysis for slowly varying (in time) fields

• Accurate TDIE for weak penetration through apertures

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

17UIUCUH

Proposed Effort (Year 1): Algorithms and Implementations

• Develop PWTD enhanced TDIE solvers with material capability (6 mo.)

• Interface PWTD enhanced TDIE solvers with SPICE-like circuit solver (12 mo.)

• Develop “low frequency” stable PWTD / TDIE solver (12 mo.)

– Hybridize loop/star/tree and time Galerkin schemes (Industry strength implementation)

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

18UIUCUH

Proposed Effort (Year 1): Demonstration of Capabilities

• Analyze coupling into a nonlinear circuit (amplifier) in a realistic enclosure (12 mo.)– Geometry: Slots, cavities, pins,

nonlinear circuitry.

– Demonstrates all capabilities of solver

– Validation: through comparison to FDTD solution.

slotcircuitry

cavityboards + pins

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

19UIUCUH

Short-Term ProblemsFast Frequency-Domain Methods

Development

• Fast frequency-domain integral equation methods for exterior-to-interior coupling problem – specialization of existing codes

• Fast frequency-domain integral equation methods for very low frequencies (for FFT)

• Fast hybrid methods -- specialization• Serve as checks of other more specialized analyses

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

20UIUCUH

EMI Threat to Aircraft SystemsAirborne Transmitter

Ground-based orship-board Transmitter

PEDSLightening

External Threat

• Coupling from other Aircraft Systems• Natural Environmental Effects (Lightening, Static Electricity)• Man Made Sources External to the aircraft (High Intensity Radiated Fields - HIRF)

Internal Threat

• Portable Electronic Devices (PEDS) carried by passengers

Picture from NASA-Langley

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

21UIUCUH

Penetration through Loaded Slots and Cracks

• Most typical coupling occurs through slots and cracks

• Closed form expressions will be developed for various 2D slots and 3D straight slots by analogy to wire scattering

• Develop an understanding of good shielding practices and relative levels of penetration among the various slots geometries

• Develop methods for equivalent circuit extraction

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

22UIUCUH

Coupling though Slots in Loaded Structure

• Develop general purpose frequency domain techniques for coupling into loaded geometries

• Validation of other techniques

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

23UIUCUH

Short-Term ProblemsApplication of EIGER

• Obtain useful information quickly – 12 months

• Develop understanding of coupling mechanisms involving moderately complex structures

• Use as a quick check on more problem-specific analyses

• EIGER will also be used for longer-term complex problems

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

24UIUCUH

EIGEREIGER May Be Used for General-Purpose EM Calculations

and Code Validation

• EIGER is a general-purpose EM modeling code being developed jointly by

U. Houston Navy (SPAWAR) Lawrence Livermore Nat’l Lab Sandia Nat’l Labs

• Special purpose codes are likely to be needed to efficiently obtain the desired parameters in some cases.

• We anticipate using EIGER to obtain initial results,validate new codes, and perform general EM modeling.

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

25UIUCUH

EIGEREIGER Takes A “Next Generation” Approach to Computational Electromagnetics

• Maintainability, extendibility, availability Current development efforts: U. Houston, U. Washington, Brigham Young, Virginia Tech

• A rich set of features allows treatment of complex problems using appropriate optimal combination of techniques

• Applicable to a wide variety of EM problems (antennas, RF, EMI, EMC, RCS, etc.)

Eiger can serve as “computational kernel” for special purpose applications, like FSSBuild, a periodic phased array and FSS

analysis interface

• High performance computing (HPC) capability incorporated into design

Object- oriented philosophy

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

26UIUCUH

Generality allows one to select the right treatment for each part of a complex problem ...

Elements

Expansions Excitation

SolversOperatorsBoundary

Conditions

ElementsGreen’sFunc.

Expansions Excitation

Solversapertureaperturecouplingcoupling

edge edge treatmenttreatment

rotationalrotationalsymmetrysymmetry

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

27UIUCUH

MURI-Related Example

Conducting Wire with 50 Loads, Terminated on Interior Walls of an Conducting Box with Two Apertures, Excited by a Voltage Source

+ -

0.4 m

0.6 m

0.36 m

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

28UIUCUH

A Variety of Boundary Conditions are Required:

•Aperture

•Conducting surface

•Wire

•Terminating loads

Effects of RF Pulses on Circuits and Systems – Pieces

UMCU UIC

29UIUCUH

A Combination of Element, Excitation, and Current Types is Needed

Element types:

triangles

quadrilaterals

wires

Possible excitation types:

interior:

voltage source

exterior:

plane wave

V

Current types:

two-sided element, ,J M

single-sided element, J

wire element, J