Patent ID: 7492243

Claim:
A planar circuit comprising: a substrate having a first surface and a second surface; a first conductor film disposed on the first surface of the substrate; and a second conductor film disposed on the second surface of the substrate, at least one of the first and second conductor films including a pattern formed region containing two-dimensionally and repeatedly arranged unit cells, each of the unit cells having rotational symmetry, wherein a center area in each of the unit cells is an inductive region, and an area located at least near a middle of each side of a peripheral portion in each unit cell is a capacitive region, and wherein the inductive region has a multiple spiral-shaped conductor pattern in which inner ends are connected to each other at a center thereof and outer peripheral ends thereof are connected to the capacitive regions, and wherein, in any two adjacent of said unit cells, the capacitive region of one unit cell is connected to the capacitive region of the other unit cell at a halfway portion between the two adjacent unit cells.