A wideband (3 to 5 GHz) wide-scan connected array of dipoles with low cross polarization

A wideband, wide-scan prototype phased array of connected dipoles has been manufactured and tested from 3 to 5 GHz. The array comprises 7 × 7 elements, each fed by a loop-shaped transformer to avoid common-mode resonances. Such resonances typically affect this type of arrays, with consequent degradation of the polarization performance. The common-mode rejection implemented by the loop transformers allows to maintain the cross-polarization levels to values lower than -10 dBs over a 30% relative bandwidth, for elevation angle up to 45° in all azimuth planes. The array exhibits a measured voltage standing-wave ratio (VSWR) lower than 2.5 from 3 to 5 GHz for broadside radiation. © 2012 IEEE.