Antenna systems with low passive intermodulation (PIM)

Exemplary embodiments are provided of antennas and antenna systems including the same. In an exemplary embodiment, an antenna generally includes an upper radiating patch element, a ground plane spaced apart from the upper radiating patch element, and a feed point positioned adjacent the ground plane. A first feeding element electrically couples (e.g., via proximity coupling or direct galvanic coupling) the upper radiating patch element to the feed point. A second feeding element electrically couples (e.g., via proximity coupling or direct galvanic coupling) the upper radiating patch element to the feed point. A shorting element electrically couples (e.g., via proximity coupling or direct galvanic coupling) the upper radiating patch element to the ground plane. In other exemplary embodiments, the antenna systems include one or more ground planes and one or more antennas.