A simple miniaturization technique using dielectric loading was applied to the design of Ultra Wideband (UWB) microstrip fed ring monopoles. The method consists of gluing a commercially available substrate layer to each metallization side. Two antenna prototypes were built and tested to validate the concept. The larger prototype covers the whole UWB bandwidth with |S11| < -10dB. The smaller has considerable reduced size, making it suitable for use in a Universal Serial Bus (USB) dongle. The larger structure was further investigated by testing the influence of a close metallic box on antenna matching.