Octave Bandwidth Printed Circuit Phased Array Element

A printed-circuit radiating element for wideband phased array antennas is described which provides a well-matched impedance bandwidth of approximately one octave in the array environment. The main benefit compared to existing octave or more bandwidth array elements (e.g. flared notch, tapered slot or Vivaldi antenna) is that this new element can be etched onto panels that lie parallel to the plane of the array, permitting several rows and columns of elements on the same substrate which reduces cost significantly. Also the array thickness is reduced, and the phase center does not move with frequency. The element can provide polarization diversity. A new low-dielectric constant syntactic foam material was also tested and found to be suitable for plated-thru via holes and bonding for microwave printed-circuits