beam-tilting improvement of balanced antipodal vivaldi antenna using a dielectric lens

conventional “balanced antipodal vivaldi antenna” (bava) usually suffers from beam-tilting at upper working frequencies. for compensating the beam-tilting, we have proposed a new bava. by adding an ovalshaped dielectric lens at the end of the antenna, the beam titling in e-plane was improved within the higher working frequencies. results show that the antenna has better than 10 db return loss for the frequency range of 3 to 18 ghz. simulated radiation patterns successfully verify the well behavior of the dielectric lens bava. for evaluating time domain characteristics, group delay and fidelity factor of the antenna is investigated.