Multiple beam crossovers for a lens-fed antenna array

Multiple beams from a linear antenna array can be formed using Ruze or Rotman lenses. A waveguide fed, parallel plate lens has been described, which provides beams with low sidelobes (¿¿20dB) and beam crossovers a¿ ¿10 dB. A microstrip version of this lens has also been described, with the additional feature of a beam port overlap network which doubles the number of beams and consequently raises the beam crossovers to ¿ ¿2dB, at the expense of a 3dB loss in the overlap network. In this paper two new networks are described, with 1.76 dB and 1.25 dB loss respectively, which increase the original number of beams from the lens fed array by 50%, and consequently provide beams with intermediate crossovers. Theoretical analysis predicts the beam crossovers as ¿ ¿4 or ¿44¿ dB for the two networks.