In this paper a single fed microstrip patch ultra-wideband rectenna for harvesting ambient radio frequency energy is presented. The rectenna comprises of a rectangular shaped radiating patch operating at L band frequencies. The rectifier circuit is placed in the same plane of radiating patch to minimize the overall rectenna profile. The rectenna is modelled and are fabricated on low loss roger dielectric substrate. Measured results shows that the rectenna attains a maximum gain of 5 dB in the operating L band with maximum RF conversion efficiency of 81%. The rectenna designed is appropriate for harvesting wireless RF signals operating in L band.