Vertical, Horizontal to Circular Polarization Reconfigurable Array Antenna with EBG Unit Cells

Abstract

An array antenna with ten Electromagnetic Band Gap (EBG) unit cells is presented. The 2.4 GHz band gap characteristics of the EBG are utilized as the reconfigurable mechanism for the antenna. The four groups of EBG unit cells incorporated to the array antenna which consists of three radiating elements namely Antenna A, Antenna B and Antenna C. The array antenna successfully alternately operated at horizontal (HP), vertical (VP) and circular (CP) polarisation with the band gap reconfigurations. The corresponding gain are 1.96 dBi, 2.67 dBi and 2.51 dBi. The axial ratio of the antenna in CP mode is 2.03 at 2.4 GHz. The EBG-incorporated array antenna is potentially suitable for 2.4 GHz ISM applications like Wi-Fi especially, in dynamic environment where different polarisation required to obtain the best transmission and reception between the transmitting and receiving antenna.