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

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) x 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 x 8 phased array stacked structures were fabricated with a volume of 0.96 lambda(0) x 6.38 lambda(0) x 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 degrees with a side-lobe level less than -8 dB.