KOSEN 한인과학기술자네트워크

High Frequency Electromagnetic Propagation/Scattering Codes Primary Sponsor: Department of Defense Deadline: 4/11/2001 KEYWORDS TECHNOLOGY AREAS: Materials / Processes OBJECTIVE: New approaches are sought for numerical implementations of high frequency (exceeding 3 GHz) approximations to Maxwell’s equations. DESCRIPTION: Because the numerical solution of the full Maxwell’s equations are not in a particularly mature state the prediction of electromagnetic scattering attributes (radar cross sections, etc) of actual-size inventory (theirs and ours) is currently provided by high frequency (exceeding 3 GHz) approximations to Maxwell’s equations such as Physical Optics (PO), Physical Theory of Diffraction (PTD) or Geometrical Theory of Diffraction (GTD). Numerical versions of these theories, the widely used code XPATCH being but one example, have various shortcomings and therefore the following improvements in numerical implementations are sought. (i) Correctly predict caustics and shadow boundaries and the wave fields (including creeping waves) which exist past such regions so that the predictions of the high frequency code are more accurate than PO/PTD/GTD in scenarios such as bistatic/multistatic radar distributions; (ii) Effectively incorporate higher order correction terms in the high frequency asymptotic expansion of Maxwell’s equations; (iii) Since PO/PTD/GTD depend so crucially on an accurate geometrical description of the scattering object (particularly the normal vectors to the object’s surface), produce an algorithm/subroutine which delivers to the main high frequency code the correct surface normals from an object’s CAD file regardless of CAD file choices/sources; (iv) Provide a rigorous analysis of the numerical error (discretization-induced dispersion for example) accompanying the preferred implementations. PHASE I: Compelling new approaches are solicited which provide some or all of the above improvements. PHASE II: A user-friendly, commercially attractive code capable of handling CAD descriptions of airplane-sized objects. PHASE III DUAL USE APPLICATIONS: An appropriate dual use application is the prediction of compatibility (minimization of interference) for commercial aircraft antennas including future GPS receivers allowing all-weather landings. REFERENCES: 1. E. Fatemi et al, Jnl Comp Phys, Vol. 120, p. 145, (1995) 2. J. Steinhoff et al, Jnl Comp Physics, Vol. 157, p. 683, (2000) KEYWORDS: High-Frequency Scattering, Computational Electromagnetics DoD Notice: Between January 2 and February 28, 2001, you may talk directly with the DoD scientists and engineers who authored the solicitation topics, to ask technical questions about the topics. The Topic Author is listed in the box below. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed after February 28, 2001, when DoD begins accepting proposals under this solicitation. TPOC: Dr. Arje Nachman, PHONE: 703-696-8427 EMAIL: arje.nachman@afosr.af.mil. After February 28, 2001 proposers may still submit written questions about solicitation topics through the SBIR/STTR Interactive Topic Information System (SITIS). If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk at (800) 382-4634 or email to SBIRHELP@teltech.com. NOTE: The Solicitations listed on this site are copies from the various SBIR agency solicitations and are not necessarily the latest and most up-to-date. For this reason, you should use the agency link listed below which will take you directly to the appropriate agency server where you can read the official version of this solicitation and download the appropriate forms and rules. The official link for this solicitation is: http://www.acq.osd.mil/sadbu/sbir/sttr01/dod_sttr01.htm. DoD will begin accepting proposals on March 1, 2001. The solicitation closing date is April 11, 2001.