On the correlation between wide-band arrays and array simulators

A ninety-six element scanning array, which operates over an octave bandwidth, has been built and tested. The array beam is steered with digital latching ferrite phase shifters, which have low insertion loss and essentially constant phase shift over considerably more than an octave. A reasonable match has been achieved through the use of dielectric transformers at both the input and radiating apertures. The array performs properly over nearly an octave bandwidth for scan angles up to 60°, but at the upper end of the frequency band, the thick dielectric transformers caused a surface wave-type phenomenon and a subsequent loss of the main beam. An examination of the occurrence of `lost beams' at scan angles of 60° showed that these effects could be predicted from simulator measurements performed at higher frequencies and smaller scan angles