A planar antenna, comprising: a ground plane extending in a first direction on a first side of a substrate; a radiating element on the first side of the substrate comprising: a first portion extending from the ground plane in a substantially perpendicular direction with respect to a direction the ground plane extends across the substrate, a second portion extending from the first portion in a substantially perpendicular direction such that the second portion extends parallel to the ground plane and defines a non-conducting slot with the ground plane, a third portion extending from the second portion in a substantially perpendicular direction such that the third portion is substantially parallel with the first portion, wherein the third portion defines a slot with the second portion, and a fourth portion extending directly from the third portion in a substantially perpendicular direction such that the fourth portion is substantially parallel with the ground plane and the second portion; and a feed line extending in a second direction on an opposite side of the substrate and overlapping the second portion, the non-conducting slot between the ground plane and the second portion and the slot between the second portion and the third portion, said feed line configured to excite at least one of said first, second, third, and fourth portions to resonate in a corresponding one of a plurality of frequency bands. a ground plane extending in a first direction on a first side of a substrate; a radiating element on the first side of the substrate comprising: a first portion extending from the ground plane in a substantially perpendicular direction with respect to a direction the ground plane extends across the substrate, a second portion extending from the first portion in a substantially perpendicular direction such that the second portion extends parallel to the ground plane and defines a non-conducting slot with the ground plane, a third portion extending from the second portion in a substantially perpendicular direction such that the third portion is substantially parallel with the first portion, wherein the third portion defines a slot with the second portion, and a fourth portion extending directly from the third portion in a substantially perpendicular direction such that the fourth portion is substantially parallel with the ground plane and the second portion; and a first portion extending from the ground plane in a substantially perpendicular direction with respect to a direction the ground plane extends across the substrate, a second portion extending from the first portion in a substantially perpendicular direction such that the second portion extends parallel to the ground plane and defines a non-conducting slot with the ground plane, a third portion extending from the second portion in a substantially perpendicular direction such that the third portion is substantially parallel with the first portion, wherein the third portion defines a slot with the second portion, and a fourth portion extending directly from the third portion in a substantially perpendicular direction such that the fourth portion is substantially parallel with the ground plane and the second portion; and a feed line extending in a second direction on an opposite side of the substrate and overlapping the second portion, the non-conducting slot between the ground plane and the second portion and the slot between the second portion and the third portion, said feed line configured to excite at least one of said first, second, third, and fourth portions to resonate in a corresponding one of a plurality of frequency bands.