Patent ID: 8081124

Claim:
A planar monopole antenna comprising: a film formed of an insulating material; an antenna element which is a single-body planar conductor on the film; and a ground element which is a planar conductor on the film and kept at ground potential, wherein the antenna element includes: a first element which is formed of a planar body of a conductive material and has a feeding point; a capacitor element having a capacitor component and a coil element having a coil component, each of which is formed of a planar body of a conductive material and formed integrally with the first element; and a second element which is formed of a planar body of a conductive material and formed integrally with the capacitor element and the coil element; wherein the first element is formed in a trapezoidal shape, and a side of the trapezoidal shape of the first element forms a predetermined angle with the ground element; wherein the second element is formed in a trapezoidal shape, and a side of the trapezoidal shape of the second element forms a predetermined angle with the ground element; wherein the capacitor element is formed by a gap section between the first element and the second element where the first element and the second elements face each other; and wherein the feeding point of the first element is provided near the gap section.