A dual band printed antenna comprising a metal substrate and an electrically isolated supporting element, wherein the metal substrate comprises a slot, wherein a side of the electrically isolated supporting element is formed on the metal substrate, characterized in that the dual band printed antenna comprises: a monopole antenna element formed on the other side of the electrically isolated supporting element and corresponding to the position of the slot, and the monopole antenna element comprises: a radiation part comprising a feed point; and a ground part separated from the radiation part for a distance; wherein the electrically isolated supporting element is plate-shaped, wherein the side and the other side of the electrically isolated supporting element are the opposite sides of the electrically isolated supporting element, wherein the radiation part is configured to resonate with the slot configured to generate a first radiation pattern of a first frequency band and the radiation part is configured to resonate itself to generate a second radiation pattern of a second frequency band; wherein the slot stretches along a specific direction, wherein two ends of the slot are within the metal substrate; wherein the radiation part and the ground part are cuboid-shaped, wherein the radiation part and the ground part stretch along the specific direction, a first end and a second end of the radiation part are respectively apart from the two ends of the slot by a first length (c) and a second length (d) that is larger than the first length, and the feed point is apart from the first end and the second end by a third length (a) and a fourth length (b) respectively; wherein a first resonant frequency of the first frequency band is adjustable by the first length and the fourth length, and a first impedance matching of the monopole antenna element corresponding to the first frequency band is adjustable by the third length; wherein a second resonant frequency of the second frequency band is adjustable by the first length and the fourth length, and a second impedance matching of the monopole antenna element corresponding to the second frequency band is adjustable by the fourth length. a radiation part comprising a feed point; and a ground part separated from the radiation part for a distance; wherein the electrically isolated supporting element is plate-shaped, wherein the side and the other side of the electrically isolated supporting element are the opposite sides of the electrically isolated supporting element, wherein the radiation part is configured to resonate with the slot configured to generate a first radiation pattern of a first frequency band and the radiation part is configured to resonate itself to generate a second radiation pattern of a second frequency band; wherein the slot stretches along a specific direction, wherein two ends of the slot are within the metal substrate; wherein the radiation part and the ground part are cuboid-shaped, wherein the radiation part and the ground part stretch along the specific direction, a first end and a second end of the radiation part are respectively apart from the two ends of the slot by a first length (c) and a second length (d) that is larger than the first length, and the feed point is apart from the first end and the second end by a third length (a) and a fourth length (b) respectively; wherein a first resonant frequency of the first frequency band is adjustable by the first length and the fourth length, and a first impedance matching of the monopole antenna element corresponding to the first frequency band is adjustable by the third length; wherein a second resonant frequency of the second frequency band is adjustable by the first length and the fourth length, and a second impedance matching of the monopole antenna element corresponding to the second frequency band is adjustable by the fourth length.