This work reports the development of a simple, low-profile and ultra-wideband printed antenna. The proposed antenna is based on a truncated ground plane and an impedance matching structure formed by a round junction and two chamfers. These modifications significantly increase the antenna frequency bandwidth compared to conventional microstrip antennas and broadband printed monopole antennas. An antenna prototype was built using a substrate of Arlon DiClad 880 and its reflection coefficient was measured and compared to HFSS numerical simulations. Good agreement between simulations and experimental results was obtained, even for higher frequencies. A K connector, which operates up to 40 GHz, was used in the antenna. The experimental results indicate a bandwidth spanning from 1.79 GHz to 28.02 GHz, representing a fractional bandwidth of 176% referred to the central frequency (i.e., 14.9 GHz).