A Novel, Real-Valued Genetic Algorithm for Optimizing Radar Absorbing Materials

By National Aeronautics and Space Administration

A novel, real-valued Genetic Algorithm (GA) was designed and implemented to minimize the reflectivity and/or transmissivity of an arbitrary number of homogeneous, lossy dielectric or magnetic layers of arbitrary thickness positioned at either the center of an infinitely long rectangular waveguide, or adjacent to the perfectly conducting backplate of a semi-infinite, shorted-out rectangular waveguide. Evolutionary processes extract the optimal physioelectric constants falling within specified constraints which minimize reflection and/or transmission over the frequency band of interest. This GA extracted the unphysical dielectric and magnetic constants of three layers of fictitious material placed adjacent to the conducting backplate of a shorted-out waveguide such that the reflectivity of the configuration was 55 dB or less over the entire X-band. Examples of the optimization of realistic multi-layer absorbers are also presented. Although typical Genetic Algorithms require populations of many thousands in order to function properly and obtain correct results, verified correct results were obtained for all test cases using this GA with a population of only four. Hall, John Michael Langley Research Center NASA/CR-2004-212669 NAS1-00135; WU 706-31-41-01 GENETIC ALGORITHMS; ARTIFICIAL INTELLIGENCE; ANTIRADAR COATINGS; DIELECTRICS; RECTANGULAR WAVEGUIDES; TRANSMISSIVITY; REFLECTANCE; CHROMOSOMES; BOUNDARY CONDITIONS; FINITE VOLUME METHOD; METHOD OF MOMENTS; SUPERHIGH FREQUENCIES; MAGNETIC PERMEABILITY; MULTILAYER INSULATION; INSULATION

• Format: Paperback
• Language: English
• ISBN: B08F6TFB21
• ISBN13: 9798672459172
• Release Date: January 1
• Publisher: Independently Published
• Length: 36 Pages
• Weight: 0.24 lbs.
• Dimensions: 0.1" x 8.5" x 11.0"