Design of Vivaldi Antenna with Ultra-wide Passband and A Band Notch

In this paper, a novel Vivaldi antenna with ultra-wide passband and a band notch without extra loading is proposed. The Vivaldi antenna is fed by a gradient microstrip line for the wideband match and has a rectangular groove at one side of the slot-line. The phase difference of the current between the two sides of the slot-line is disturbed seriously as the length of the rectangular groove is close to a quarter wavelength at the suppressed frequency. Therefore, the antenna obtains adjustable band notch characteristic by simply changing the length of the rectangular groove. Simulation results show that the proposed antenna provides ultra-wide bandwidth as well as a notch inside the passband with good narrow band suppression.