Disclosed are exemplary embodiments of omnidirectional broadband antennas. In an exemplary embodiment, an antenna generally includes a ground element, an antenna element, and an annular patch element. The antenna element may be electrically isolated from the ground element. The antenna element may include at least one portion that is substantially conical, substantially pyramidal, and/or that tapers in a longitudinal direction. The annular patch element is electrically grounded to the ground element. The annular patch element surrounds at least a portion of the antenna element and is parasitically coupled to the antenna element.