Abstract-For the first time, we demonstrate the feasibility of realizing ultrawideband antennas through ink-jetting of conductive inks on commercially available paper sheets. The characterization of the conductive ink as well as of the electrical properties of the paper substrate are reported for frequencies up to 10 GHz. This letter is one step further toward the development of low-cost, environment-friendly conformal printed antennas/electronics for ad hoc wireless sensor networks operating in rugged environments.