Patent ID: 8830126

Claim:
An apparatus having multiple mushroom structures, each of the multiple mushroom structures including: a ground plate; a first patch provided parallel to the ground plate with a separation of a distance to the ground plate; and a second patch provided parallel to the ground plate with a separation of another distance to the ground plate, which another distance being different from the distance from the first patch to the ground plate, wherein the second patch is a passive element which is capacitatively coupled with at least the first patch, a gap between first patches of neighboring mushroom structures out of a certain number of mushroom structures lined up along a certain line gradually changes along the certain line, and a distance from an end of one of neighboring first patches for determining the gap to a reference line of the one of the first patches equals a distance from an end of the other of the neighboring first patches to a reference line of the other of the first patches, and a distance between reference lines to multiple mushroom structures is uniformly maintained.