A ground pattern includes a plurality of integrally formed first to third ground lines. A plurality of first ground lines are arranged parallel to one another at equal intervals. A plurality of second ground lines are arranged parallel to one another at equal intervals between adjacent ones of the first ground lines. A plurality of third ground lines are arranged parallel to one another at equal intervals between adjacent ones of the first ground lines at a predetermined angle with respect to the second ground lines. The third ground lines each connect one end of one adjacent second ground line with the other end of another adjacent second ground line. The ground lines form triangular openings.