A planar monopole antenna for dual-band Wi-Fi application is disclosed. The antenna has a ground copper and a radiation copper. The radiation copper is adhered to a substrate and has an arrowhead-shaped pattern connected to a long-wide pattern. The arrowhead and long-wide patterns are aligned along the longitudinal direction of the antenna. The ground copper is adhered to the substrate and has a rectangularly-shaped pattern with an opening at one end thereof for the reception of the base of the long-wide pattern of the radiation copper in the longitudinal direction. Reception of the radiation copper into the opening of the ground copper forms an U-shaped separation that is approximately 0.6 mm wide. The antenna has a gross span of approximately 45 mm and a width of approximately 7 mm.