Multiple beam stripline network for phased array applications

The design and manufacture of printed beamformer components for an I-band (~9 GHz) phased array are described, together with some measured results. A 5000 element phased array has been designed employing monopulse tracking techniques and capable of scanning out to ±45° over a conical volume of scan. Elevation sum (Σ) and difference (Δ) beams are generated using an etched stripline circuit incorporating digitally controlled, 3-bit phase shifters to scan the beam. Azimuth Σ and Δ beams are formed in a waveguide network feeding into the elevation networks via `magic tee´ couplers. Waveguide is used in the early stages of the beamforming network because of the high power handling requirement in a full sized, operational array. Dielectric filled stripline may be used for the elevation networks where power is distributed over many boards