The main limitation of any chipless Radio Frequency Identification (RFID) system is the very short reading range. In this paper, we propose an Ultra Wideband (UWB) Reflectarray Antenna (RA) system with 2.2 GHz bandwidth centered at 6 GHz for the reader of chipless RFID applications. The proposed reader antenna system enhances reader sensitivity, reduces multipath effects, helps in tag localization and a lot of novel capabilities that cannot be provided by the conventional antenna systems. The cell used in the design is the double circular ring where the antenna panel consists of 100 elements (10×10). Simulations show that the proposed antenna system reaches fractional bandwidth (FBW) 37% covering all the feeder bandwidth. This achieved ultra wide bandwidth (UWB) satisfies the requirements of the frequency signature based chipless RFID systems.