Apparatus having mushroom structures

摘要

An apparatus having multiple mushroom structures is disclosed. Each of the multiple mushroom structures including: a ground plate (21); a first patch (23) provided parallel to the ground plate (21) with a separation of a distance to the ground plate (21); and a second patch (24) provided parallel to the ground plate (21) with a separation of another distance to the ground plate (21), which another distance being different from the distance from the first patch (23) to the ground plate (21), wherein the second patch (24) is a passive element which is capacitatively coupled with at least the first patch (23).