Ring Phased Array Based Millimeter-Wave Ultra-Wideband Hemispherical Dielectric Resonator OAM Antenna

With the development of wireless communication technology, modern mobile communication technology has entered the new era of fifth-generation mobile communication technology (5G), and large bandwidth is required to meet the high speed of 5G to transmit data. Moreover, the shortage of spectrum resources and low spectrum utilization are still important factors that hinder the development of wireless communication technology, so how to solve the above problems and apply them to the 5G system becomes a current research hotspot. In this paper, a millimeter-wave ultra-wideband compact OAM dielectric resonator array antenna working in Ka-band is designed based on the ring-phased array antenna model and the OAM vortex electromagnetic wave generation principle. The antenna is coaxially fed by loading eight identical hemispherical dielectric antennas on the dielectric plate, and the adjacent array units are rotated 45° along the clockwise direction. The experimental results show that under the condition of equal amplitude and phase feeding of the array elements, the antenna array can generate a multimodal OAM beam at 25 GHz with a relative bandwidth of 79.5 % at -10 dB, achieving ultra-wideband, multimodal, and miniaturization, and is suitable for 5G systems.