Design of Planar ESPAR Antenna by Using Sidelobe Reduction Algorithm

Planar electronic steering passive array radiator (ESPAR) antenna for wireless mobile terminals is proposed in this paper. To achieve conical elevation pattern and compact size, a modified central grounded hexagonal patch antenna is utilized. A robust sidelobe reduction (SLR) adaptive algorithm is invented to optimize the reactive load for each passive element. Fabrication and measurement have been carried out to validate the advantages of this antenna, experiment results show that the planar ESPAR antenna has good capacity of pattern steering in azimuth, the gains of antenna are better than 7 dBi in three different directing cases, azimuth pattern and elevation pattern at desired direction have been measured and present excellent performances.