Aperture-Shared Design of Millimeter-Wave Phased Array and Sub-6 GHz Antenna Using Diversified Metasurface Structures

This article presents a novel aperture-shared architecture applied in integration of millimeter-wave (mmW) phased array and sub-6 GHz antenna using diversified metasurface structures. First, a miniaturized mmW antenna element based on overlapped metasurface is designed, and then a wide-angle scanning phased array using the above elements is constructed with some U-shaped decoupling paths. In addition, a novel electromagnetic-transparent (EM-transparent) sub-6 GHz antenna formed by four square ring metasurface (SRMS) cells is proposed and located above the mmW array in the same aperture. To further reduce the shielding effects, a serial of frequency-selective surface (FSS) structures with high-impedance property are loaded around the SRMS for enhancing the transparent property at mmW band. Finally, the aperture-shared antenna array is implemented using the low-temperature-cofired ceramic (LTCC) technology; moreover, their feeding networks are highly integrated together. As a result, the mmW array can achieve a wide beam scanning in the E-plane from −55° to 55° at 24.25–29.5 GHz and high isolation over 20 dB; meanwhile, the sub-6 GHz antenna exhibits good radiation at 3.3–3.6 GHz. Compared with other works, it not only realizes aperture-shared integration of mmW phased array and sub-6 GHz antenna with largest frequency ratio but also ensures wide-angle scanning performance, which can be potentially applied in future multiband base-station antennas.