Antipodal Vivaldi antenna with tuneable band rejection capability

An antipodal Vivaldi antenna with tuneable band reject capability is presented. The antenna presented has the capability to operate over the bandwidth 1.5–4.3 GHz at return loss <−10 dB, but with a tuneable rejection band, the centre frequency of which may be varied in the range 1.8–2.8 GHz enabling rejection of cellular and ISM bands. Within this frequency range the return loss at the centre frequency of the rejected band varies from −2.7 to −4.1 dB. Farfield measurements show that radiation patterns are disrupted only within the rejected band and remain largely unaltered outside the rejected band.