Direction-of-arrival estimation (DoA) using switched parasitic planar arrays and the method of genetic algorithms

An electronically controllable, switched parasitic planar array can be used for the purpose of direction finding. The method proposed in this paper exploits the electronic beam steering, achieved by simply inserting an appropriate digital word in the antenna feeding circuit, to resolve two signals. A genetic algorithm was used to determine the strengths and the angular positions of the incoming signals in the azimuth plane. The results obtained concentrate on wideband signaling in a multipath environment, with and without the presence of noise. The antenna design and the reliability of the direction-finding method are presented. The proposed method is strongly dependent on the type of the receiving antenna (a switched parasitic planar array is superior to a "uniform" antenna with identical radiation patterns). Increasing the number of radiation patterns available improves the reliability of the method. The reliability of the method slightly deteriorates, as the angular discrimination of the incoming signals becomes smaller, but the results remain quite satisfying.