A multiband antenna comprising a substrate having first and second surfaces. A first conductive plate located on the first surface comprises a first conductive region couplable to ground by a shorting element, and a second conductive region. The first and second conductive regions are located to define a gap therebetween. The antenna also has a second conductive plate on the substrate's second surface. The second conductive plate is coupled to a signal terminal of a feeding port and positioned to provide capacitance with the first conductive region. The antenna also has a third conductive plate on the substrate's second surface. The third conductive plate is positioned to provide capacitance with the second conductive region, and a connecting conductor configured to electrically couple the third conductive plate to the second conductive region.