High Gain and Low-Profile Stacked Magneto-Electric Dipole Antenna for Phased Array Beamforming

Abstract

A high gain stacked antenna based on a planar magneto-electric dipole structure is proposed. The main radiator is configured by a probe-fed patch with a symmetrically arranged pair of dipole radiation elements. Further, an additional air-gapped radiator with multiple patch elements is integrated for gain enhancement. Since both the main and stacked radiators are planar structures, the overall volume can remain low-profile regardless of the airgap. To verify the performance of the proposed structure, a single magneto-electric dipole antenna and three different types of stacked radiators were implemented at 5.8 GHz. The magneto-electric dipole antenna showed measured 10-dB impedance bandwidth and gain of 5.2% and 8.0 dBi, respectively with the overall size of $0.96\,\,\lambda _{0} \times 0.96\,\,\lambda _{0}$ including a ground plane. With the additional stacked radiator having the airgap of $0.1~\lambda _{0}$ , the maximum measured gain was increased to 9.6 dBi. Further, to verify the beamforming performances, three types of $1\times 8$ phased array stacked structures were fabricated with a volume of $0.96\,\,\lambda _{0} \times 6.38\,\,\lambda _{0} \times 0.14\,\,\lambda _{0}$ at 5.8 GHz. The measurements showed a maximum peak gain of 18.1 dBi and a half-power-beamwidth scan angle of 49° with a side-lobe level less than −8 dB.