Methods and systems are provided for implementing and utilizing dual-polarized planar ultra-wideband antennas. An example planar antenna may include a substrate, a monopole conductor, a first ground conductor, and a second ground conductor. The monopole conductor may be connected to a first signal feeding line. The first ground conductor may be connected through a ground connector to ground potential. The first ground conductor may be further connected to a second signal feeding line. The second ground conductor may connected to ground potential located on a particular side of the substrate. The planar antenna may be configured to transmit and receive radiation in two mutually cross-polarized modes.