Improvement of far field patterns of antipodal vivaldi antennas with step impedance resonator

This paper investigates the effects of step impedance resonator (SIR) on the bandwidth broadening and improvement of far field pattern of antipodal Vivaldi antenna. The antenna designed has the impedance bandwidth from 5.5GHz to beyond 30GHz, which covers from the X band to Ka band. This new configuration for the edge comb is presented which improves the front-to-back ratio of the antenna over the operating frequency 5.5 GHz to 30.0 GHz.