A Four Bandwidth-Resolution UWB Antipodal Vivaldi Antenna
In this paper, a frequency reconfigurable Antipodal Vivaldi Antenna (AVA), capable of covering a Band of Interest (BoI) spanning from 3 to 10.6 GHz with four different bandwidth resolutions, is presented. By incorporating four rectilinear resonators and two Split-Ring-Resonators (SRRs) into the AVA, the whole BoI can be covered by one (UWB mode), three (3-sub mode), seven (7-sub mode), or sixteen (16-sub mode) sub-bands. In the UWB-mode, all the six resonators are deactivated by disrupting their structures, so the antenna operates as a classical AVA. In the 3-sub mode, only one rectilinear resonator is activated; the low Q of these resonators allow narrowing the antenna operating band so that the BoI is covered by three sub-bands. In the 7-sub mode, two rectilinear resonators are activated at a time, which narrows the operating bandwidth furthermore, allowing to cover the BoI by seven sub-bands. In the 16-sub mode, one of the two SRRs is activated at a time to be used as a coupling-bridge to very narrow frequency bands that allows covering the BoI by sixteen different bands. To present the work, simulated and measured results are given and discussed.