Electromagnetic band gap-dipole sub-array antennas creating an enhanced tilted beams for future base station

Abstract

A novel customised electromagnetic band gap (EBG)-dipole sub-array antenna with a tilted beam for future basestation applications is presented. An enhanced tilted beam for the base-station antenna is one of the safest methods to increase radio coverage area adhering to the strict power requirements. An array of four dipole-EBG elements is designed demonstrating the enhanced down-tilt beam. Each single element consists of dipole antenna mounted on a customised EBG ground plane created by connecting several unit cells of the EBG. The proposed array radiates a tilted beam in order to achieve a high directivity at fixed down-tilt angle. The array antennas are simulated, fabricated and measured. The directivity of 11 dB is measured at the angle of 28° at 3.5 GHz. This directivity is 1.9 dB higher than the reference case that uses the broadside single element. In addition, the EBG-dipole array that can be mechanically tilted is designed. The proposed array antenna exhibits acceptable impedance matching across the operational frequency band.