Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. (From -To)
REPORT DATE (DD-MM-YYYY)
23-08-2007
REPORT TYPE:
Conference Paper
DATES COVERED
SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)Electromagnetics Technology Division Source Code: 437490
SPONSOR/MONITOR'S ACRONYM(S)Sensors Directorate AFRL-SN-HS Air Force Research Laboratory 80 Scott Drive Hanscom AFB MA 01731-2909
SPONSOR/MONITOR'S REPORT NUMBER(S)
AFRL-SN-HS-TP-2007-0010
DISTRIBUTION / AVAILABILITY STATEMENTStatement A: Approved for Public Release; distribution unlimited.
SUPPLEMENTARY NOTES
This work is copyrighted. © [2007] Society of Photo-Optical Instrumentation Engineers (SPIE). Presented at 2007 SPIE Defense andSecurity Symposium, Orlando, FL, 9 -13 April 2007. One or more of the authors is a U.S. Government employee working within the scope of their Government job; therefore, the U.S. Government is joint owner of the work and has the right to copy, distribute, and use the work. This work is supported by AFOSR; ESC/PA clearance: ESC 07-0394
ABSTRACTThis paper describes the application of biologically-inspired algorithms and concepts to the design of wideband antenna arrays. In particular, we address two specific design problems. The first involves the design of a constrained-feed network for a Rotman-lens beamformer. We implemented two evolutionary optimization (EO) approaches, namely a simple genetic algorithm (SGA) and a competent genetic algorithm. We conducted simulations based on experimental data, which effectively demonstrate that the competent GA outperforms the SGA (i.e., finds a better design solution) as the objective function becomes less specific and more "general." The second design problem involves the implementation of polyomino-shaped subarrays for sidelobe suppression of large, wideband planar arrays. We use a modified screen-saver code to generate random polyomino tilings. A separate code assigns array values to each element of the tiling (i.e., amplitude, phase, time delay, etc.) and computes the corresponding far-field radiation pattern. In order to conduct a statistical analysis of pattern characteristics vs. tiling geometry, we needed a way to measure the "similari...