SBIR-STTR Award

RF Cavity Response: Statistics, Data Acquisition, and Circuit Analysis
Award last edited on: 10/10/2002

Sponsored Program
SBIR
Awarding Agency
DOD : AF
Total Award Amount
$792,602
Award Phase
2
Solicitation Topic Code
AF94-083
Principal Investigator
Richard Holland

Company Information

Shield Rite Inc

PO Box 8250
Albuquerque, NM 87198
   (505) 842-6018
   N/A
   N/A
Location: Single
Congr. District: 01
County: Bernalillo

Phase I

Contract Number: ----------
Start Date: ----    Completed: ----
Phase I year
1994
Phase I Amount
$79,198
Contractor will implement techniques for combining EM coupling codes and circuit analysis codes to determine transfer functions from HPM threats (cw and pulsed) to circuit component responses. Techniques will be general enough to treat pulse rise time, total energy, and duration. Treatment will be general enough to work for friendly or unfriendly satellites. Coupling through antennas, sensors, leaky walls, and apertures will be permitted. Contractor will treat the exterior coupling, the RF points of entry, the internal response, the internal RF coupling to cables and circuits, and the circuit response as associated, but separable, problems. An effort will be undertaken to extend the EM regime previously considered subject to probabilistic analysis. This extension will include topics such as probabilistic representation of external coupling, crack and aperture definition, and EM penetration through such p.o.e.'s. Deterministic treatment of p.o.e. EM penetration and of the external coupling will also be considered, but the internal response will only be treated statistically. Contractor will explore application of probabilistic techniques to scenarios where the overmoding assumption may not hold. This exploration will be performed assuming that field distributions are approximately log normal with a chi square upper tail even if the overmoding assumption is not met.

Phase II

Contract Number: ----------
Start Date: ----    Completed: ----
Phase II year
1995
Phase II Amount
$713,404
The overall goal of this work is to develop a PC-controlled system that can give the user the capability to anticipate and model the statistical distribution of internal EM fields, cable currents, and the resulting circuit responses of an enclosed asset. This will be accomplished by a mixture of experimental and analytical techniques. EM field statistical characterization is the first milestone. These distributions are log normal, chi square, or some mixture of the two. If the asset is accessible, this field characterization will be obtain by a PC-controlled network analyzer which transmits RF signals, senses the asset's response, and reduces the data to probabilistic fits. If the asset is inaccessible, probabilistic techniques will be employed to characterize the external RF interference, compute the external coupling and P.O.E. transfer functions, and thus estimate numerically the internal RF field distribution. These statistically characterized internal EM fields will then serve as drivers to a circuit-analysis or cable-analysis code such as SPICE. All analysis above the circuit level will be probabilistic, and no appeal will be made to FDTD procedures, as they become inadequate for short wavelengths or complex wiring harnesses. Both time- and frequency-domain software will be maintained, although our front-line software will be time-domain to accommodate possible nonlinear circuit components. The overall package will be first tested at the EMPTAC facility, and then on any enclosed system which a potential customer desires to see us characterize. Software will also be written to display the system output in a maximally informative graphical format.