Abstract: Disclosed are exemplary embodiments of a low profile wideband and/or multiband omnidirectional antennas. In an exemplary embodiment, an antenna generally includes a radiator and a ground plane. The ground plane may include a slanted surface along or defining an edge portion of the ground plane. The slanted surface may be configured to be operable for reducing null at azimuth plane to thereby allow the antenna to have more omnidirectional radiation patterns for the azimuth plane. In another exemplary embodiment, an antenna generally includes a substrate, a radiator along the substrate, and electrically-conductive tape or foil defining at least part of a ground plane. The electrically-conductive tape or foil is coupled to a ground of the radiator via proximity coupling and electrically insulated by masking of the substrate.