Wideband High-Gain Metasurface Antenna Array Loaded With Substrate Integrated Cavity for X-Band Applications

A wideband high-gain metasurface (MTS) antenna array loaded with substrate integrated cavity (SIC) is proposed. Benefiting from the wideband property of MTS-based structures and the high gain property of SIC structure, a novel wideband high-gain MTS antenna element is designed. By utilizing the slot mode, TM10 mode of the MTS, and the TM121 mode of the SIC, the cavity-backed slot-coupled MTS radiation mechanism and the high-order mode (HOM) SIC radiation mechanism are combined to realize wideband and high-gain radiation. A parametric study is conducted to investigate the design process. The simulated results of the proposed antenna element present an overlaid bandwidth of 40.3% from 7.43 to 11.18 GHz and a maximum gain of 10.40 dBi at 11.00 GHz. On this basis, a planar $4\times 4$ array fed by a two-layer feeding network based on substrate integrated waveguide (SIW) power divider is designed and fabricated. The measured results indicate that the proposed array has an overlaid bandwidth of 34.8% from 7.95 to 11.30 GHz, a measured gain of up to 19.90 dBi, and a maximum aperture efficiency of 80.0%.