Design on quasi-Yagi antennas array based on genetic algorithm

As radiating elements for a phased array consisting of radiating elements placed along a straight line, a quasi-Yagi antenna that has a reflector behind the dipole and a parasitic element in front is used. The length of the parasitic elements and the distance between the parasitic element and the dipole are optimized by the genetic algorithm in such a way that the gain deterioration due to beam scanning is the minimum. Further, the quasi-Yagi antenna is applied in the array antenna for direction-of-arrival estimation using such subarrays as ESPRIT. The parameters optimizing the direction-of-arrival estimation accuracy are derived by the genetic algorithm. The array antenna with quasi-Yagi antenna optimized by the genetic algorithm can significantly improve the beam scanning characteristics and improve the accuracy and resolution when used for direction-of-arrival estimation by ESPRIT This is confirmed by computer simulation and test evaluation. (C) 2003 Wiley Periodicals, Inc.