Abstract: Vivaldi antenna is an exponentially tapered slot antenna (ETSA), is easy to fabricate and can provide wide bandwidth. In this research work design of a TSA has been discussed which is Vivaldi antenna for UWB frequency using FR4 substrate which has permittivity of 4.4. In this design of Vivaldi antenna the UWB frequency cover from 1.2 to 4.8 GHz. This design is simulated by the CST software. For TWI the return loss S11 should be below -10dB, which is very easily obtained in this design.

Keywords: UWB, Vivaldi antenna, FR4 substrate, TWI, ETSA.