Design and optimization of a multipurpose tri-band Electronically Steerable Passive Array Radiator (ESPAR) antenna with steerable-beam-pattern for maximum directionality at the frequencies of 1.8, 1.9 and 2.4 GHz with the aid of genetic algorithms

The development of ESPAR antennas is a progressing research area which will play a significant role in commercial mobile communications applications. In this paper the performance of an electronically steerable passive array radiator (ESPAR) antenna, with cylindrical skirt regarding the horizontal radiation pattern, suitable for both mobile telephony (1.8 and 1.9 GHz) and WiFi/WLAN (2.4 GHz) applications is presented. An effort is carried out to optimize the performance of this structure regarding its resonant frequencies and the formation of a directional beam to a predetermined direction with the aid of the genetic algorithms (GA) technique. Due to their limited physical size, these antenna systems can be developed for application in the areas of mobile telephony, WiFi and ad hoc wireless networks.