Equivalent circuit of twin Vivaldi antenna fed by coplanar waveguide

A coplanar waveguide-fed twin Vivaldi antenna has been developed and tested at 4.4 GHz and an equivalent circuit has been proposed. E-plane radiation patterns show a centred zero because of the odd excitation of the antennas while low cross-polarisation levels are observed. The maximum radiation angle can be modified by adjusting the distance between the antennas. The equivalent circuit will be useful for the design of a parallel series-fed array of Vivaldi antennas