Very wide-band phased-array antenna

An experimental 95-element phased-array antenna is described that has been matched to operate over nearly an octave. Techniques used in designing the aperture-matching networks are discussed and experimental results are presented. The array aperture is formed by broad-band digital latching ferrite phase shifters in a closely stacked triangular configuration. For experimental convenience the array is horn fed from the rear. Matching of this antenna was accomplished by placing double-step dielectric transformers on the input and radiating apertures. Resonances caused by the dielectric transformer on the aperture are discussed. The array operates from 3.5 to 6.5 GHz with scanning to
\pm 60\deg
in all directions. The bandwidth is limited at the low end by magnetic resonance of the ferrite phase shifter and at the high end by the aperture resonance.