A compact ultra wide band antenna with band notched characteristics is presented in this paper. Single band notch is created in 5.4 GHz to 6.4 GHz frequency region with the help of two C shaped slots in order to reduce the interference in WiMax and X-band systems. A good return loss (S11) values have been noted in WiMax (5.1 GHz to 5.8 GHz) and X-band (7.1 GHz to 7.7 GHz) frequency range. The designed antenna covers the ultra wide band range of 3.1 GHz to 10.6 GHz which has VSWR less than 2 and the return loss is less than -10db and has an omni-directional radiation pattern. The designing and simulation results are done by using ANSOFT High Frequency Structure Simulator. A prototype was fabricated on FR4 substrate and measurements were done using Agilent N9916A Fieldfox handheld vector network analyzer
