1. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 1 UIUCUH MURI Team Experience in EM Penetration and Coupling Pieces

2. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 2 UIUCUH MURI Team Experience Wires and Apertures PenetrationAccuracy Enhancement Coupling Building Penetration Time Domain Methods FDTDFast Methods Integral Equations Freq. Domain Methods Cavity Penetration Block House Penetration Backdoor Entry Nonlinear Loads Exterior Problems Experimental Verification

3. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 3 UIUCUH Wires, Apertures, Conducting Surfaces Wire through hole in conducting screen Wire excited through aperture in conducting screen Penetration through arrays of slots Wire-to-wire coupling through slot in screen

4. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 4 UIUCUH Wire through Hole in Conductor

5. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 5 UIUCUH Wire through Hole in Conductor

6. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 6 UIUCUH

7. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 7 UIUCUH Figure 5.16. Magnetic current induced in vent slot due to dipole-spot excitation LIME excitation of vent slots

8. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 8 UIUCUH Wires coupled via a Slot in a Screen

9. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 9 UIUCUH

10. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 10 UIUCUH

11. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 11 UIUCUH Penetration into and Radiation from Enclosures through Apertures Penetration into box via slot in sidewall Penetration through loaded aperture Coupling to wire in slotted conducting tube Coupling to wire in box through slot in wall Wire in box with slots in sidewall -- EIGER

12. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 12 UIUCUH Electric Field Shielding (dB): Validation of MLFMM code EMCAR y x z EyEy k 30 cm 12 cm Rectangular Aperture 20 by 3 cm Measured at Center of cavity Note that at resonance relative coupling is increased by 20dB as compared to ambient field

13. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 13 UIUCUH Transmission Through Loaded Apertures Transmission vs. Incidence Angle Transmission vs. Frequency

14. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 14 UIUCUH Coupling to a Wire Near a Slotted Cylinder

15. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 15 UIUCUH Plane Wave Exciting Wire in Slotted Tube

16. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 16 UIUCUH Analysis of a Probe Inside a Slotted Cavity

17. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 17 UIUCUH Corroboration of Computed Data

18. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 18 UIUCUH Results EIGER (preliminary results) Measurement (IEEE Trans. EMC, May 1994, pp. 144 -146) Normalized output current for a 1 V source + - 0.4 m 0.6 m 0.36 m

19. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 19 UIUCUH Accurate Methods—Assurance of Accuracy Penetration into slotted rectangular tube – 2D Coupling to probe in nose cone of “mock” missile

20. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 20 UIUCUH Weak Penetration Study

21. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 21 UIUCUH Weak Penetration Study Far-zone electric field due to the probe inside mock missile with partially closed nose cone: h c = 14.6 cm, h b = 118.7 cm, a= 0.0787 cm, b= 7.875 cm, c= 0.2286 cm, d= 4.25 cm, e= 3.1 cm.

22. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 22 UIUCUH Penetration into Buildings Penetration through composite wall – concrete with rebar “shield” Composite transfer function

23. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 23 UIUCUH Modeling of EM Field Penetration into Buildings Computed Transmission (dB) Measured Transmission Simple models for field penetrations into complex facility walls have been developed, using previously measured data

24. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 24 UIUCUH Modeling of EM Field Penetration into Buildings (con’t.) Example of the transfer functions for a rebar shield alone, one and two layers of concrete (each 0.102 m thick with  r = 1,  r = 1,  = 0.1 S/m), and the composite rebar/concrete shield.

25. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 25 UIUCUH Time Domain Methods, Fast Methods Penetration through curved slots Fast time domain integral equation (TDIE) methods–penetration into enclosures “Low frequency” considerations of TDIE Accommodate nonlinear loads Finite difference time domain (FDTD) methods

26. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 26 UIUCUH Curved Slot in Conducting Surface

27. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 27 UIUCUH

28. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 28 UIUCUH Penetration through Slotted Surface

29. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 29 UIUCUH Rapid time domain analysis of motherboards/cards, (partial) enclosure, pins,… Approx. 10K spatial unknowns Broadband analysis = 2 hours Fast TDIE analysis: EMC of enclosures

30. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 30 UIUCUH Fast TDIE analysis: EMC of enclosures (Cont) Radiated power for different configurations Power (dBmW) f (GHz) Ventilation slot emissions 17.5 cm 4.5 cm 25 cm 5 cm 10 cm 1 cm 20 cm 30 cm 15 cm Chassis + motherboard + cards

31. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 31 UIUCUH Fast TDIE analysis: low frequency aspects Rapid time domain analysis of motherboards with traces, cables, gaps, etc Approx. 3K spatial unknowns Broadband analysis = 30 mins Using stable TDIE schemes –Galerkin testing in time (Nedelec / Volakis) –Loop star decompositions Contrary to FDTD: no timestep limitation (CFL >>> 1)

32. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 32 UIUCUH NA Fast TDIE analysis: low frequency aspects (Con’t.) 2mm 30 cm 20 cm  Excitation fmax = 1 GHz  at fmax = 0.3 m  ds at fmax = /300  /10  Comparison of computed |S21| to the measured result *

33. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 33 UIUCUH Fast TDIE analysis: nonlinear circuitry We have developed a capability for analyzing lumped nonlinear elements in within TDIE framework.varistors Current (kA) Voltage (kV) Magnitude (kV) Voltage on the varistor Voltage on the varistor 5 m 0.1 m 500  0.02 m

34. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 34 UIUCUH Finite Difference Time Domain (FDTD) Modeling Investigation of EM fields radiated from a localized source inside a buried facility Problem Geometry 3-Dimensional FDTD Model

35. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 35 UIUCUH Finite Difference Time Domain (FDTD) Modeling (Con’t.) Tangential E-field at earth surface at t = 65.8 ns Radiated E-field in far zone

36. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 36 UIUCUH The Exterior Problem, Fast Frequency Domain Methods Leakage of field from exterior to interior through cracks, seams, and holes Leakage of field from exterior to interior through antennas Fast frequency domain methods (FD) for “massive problems”

37. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 37 UIUCUH EMI Threat to Aircraft Systems Airborne Transmitter Ground-based or ship-board Transmitter PEDS Lightening 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

38. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 38 UIUCUH Antenna Simulation on Full Scale Aircraft

39. Effects of RF Pulses on Circuits and Systems – Pieces UMCUUI C 39 UIUCUH Coupling through Antennas Antennas are ‘doors’ to coupling from external excitations into the aircraft, tanks, missiles, ships, control centers, etc. For coupling studies, details such as wires, feed structures and loadings are crucial