Patent ID: 8847822

Claim:
An apparatus having multiple mushroom structures arranged in a grid of rows and columns, each of the multiple mushroom structures including: a ground plate; and a patch provided parallel to the ground plate with a separation of a predetermined distance to the ground plate, wherein each of multiple rows of the grid includes at least two mushroom structures and a middle mushroom structure disposed between the at least two mushroom structures, in each of the multiple rows a patch of the middle mushroom structure overlaps patches of the at least two mushroom structure by an overlap amount, and the overlap amount is different for each of the multiple rows, wherein the grid includes rows with a gap between patches of neighboring mushroom structures out of a certain number of mushroom structures, and the gap gradually changes from row to row, and wherein 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.