A slot antenna includes a dielectric substrate, a conductive layer, a slot and a feeding strip. The dielectric substrate includes a first surface and a second surface opposite the first surface. The conductive layer is positioned on the first surface of the dielectric substrate, and is configured to electronically couple to ground. The slot is defined in the conductive layer and terminates on an edge of the conductive layer. The feeding strip is positioned on the second surface of the dielectric substrate and extends across the slot. The feeding strip is configured to feed current signal and resonate with the conductive layer.