An antenna includes a substrate having a first layer, a second layer, a third layer and a fourth layer, and an antenna unit having a first pattern being of a substantially coiled shape and printed on the first layer, a second pattern being of a meandering shaped and printed on the second layer, a third pattern being of a meandering shaped and printed on a third layer, and a fourth pattern being of a substantially coiled shaped and printed on the fourth layer. The first pattern, the second pattern, the third pattern and the fourth pattern are of a serial connection. The free end of the first pattern connects a feeding point. The free end of the fourth pattern connects a grounding point. Thus, the antenna has advantages of compact size and low cost, due to the antenna unit printed on the substrate and the pattern of the antenna unit.