Embodiments include antenna systems capable of producing high quality circularly, elliptically, or linearly polarized radiation. Embodiments include single feed (single-ended or differential) or multiple feed antennas. Embodiments can be electronically configured to adjust the type of polarization of the antenna system. In an embodiment, the polarization of the antenna system is adjusted by adjusting at least the position of a grounding node relative to the position of a feed node. In another embodiment, the polarization of the antenna system is adjusted by configuring one or more input nodes of the antenna between feed nodes, grounding nodes, and open nodes. In another embodiment, the polarization of the antenna system is adjusted by adjusting the phase of a single differential feed of the system.