A Compact Wideband Low-Profile Metasurface Antenna Loaded with Patch-Via-Wall Structure

This letter designs a miniaturized low-profile metasurface (MS) antenna with compact size, large bandwidth, and stable gain. First, a miniaturized MS structure using the via-wall capacitive loading is investigated. Different from the traditional square MS structure, this design loads via walls on both sides of the square patch to introduce large equivalent parallel-plate capacitance, which can reduce the size of the MS element by 50%. The stacked patches are then loaded horizontally along the side via walls to introduce additional edge capacitance for a further 10% size reduction. Finally, a miniaturized patch-via-wall MS element with small size of 0.061λ0×0.061λ0 can be obtained. For demonstration, the proposed miniaturized patch-via-wall MS structure is applied to realize a compact wideband antenna fed by a microstrip line through a coupling slot. Measured results show that the proposed patch-via-wall MS-based antenna can achieve a large impedance bandwidth of 43.1% (5.46-8.46 GHz), a small aperture size of 0.348λ0×0.348λ0 with a high gain of 6.18 dBi, and a thin thickness of 0.07λ0.