This paper presents a simple broadband proximity-coupled microstrip patch antenna. A circular patch is used as the main radiator, and an H-shaped shot is cut in the ground plane below the feed line. A stepped-width microstrip line is used to feed the patch through proximity coupling. By using a single patch, the prototype antenna achieves an impedance bandwidth of 26%. Low cross-polar levels below -20 dB are observed in both E- and H-planes. The broadband antenna is planar, small size, simple in structure, low in cost, and easy to be fabricated, thus attractive for practical applications.