Multi-octave phased array for circuit integration using balanced antipodal Vivaldi antenna elements

A novel wide bandwidth antenna designed for use in integrated phased arrays is described. The balanced antipodal Vivaldi antenna exhibits a very wide bandwidth combined with low cross polarisation and this performance is well suited for use in EW systems. Measured performance of this new antenna is compared to both the conventional Vivaldi and the antipodal Vivaldi antennas. It is shown that the new antenna has major advantages over the Vivaldi in terms of increased bandwidth capabilities and over the antipodal Vivaldi in terms of improved cross polar performance. Initial results are presented for a seven element linear array using elements made on high permittivity substrate. Analysis using the FDTD method is used for both element optimisation and to provide insight into the antenna operation.