A 3- to 5-GHz Wideband Array of Connected Dipoles With Low Cross Polarization and Wide-Scan Capability

A wideband, wide-scan phased array of connected dipoles has been designed and fabricated. Measured results from a 7 7 prototype demonstrator are presented for experimental validation. In order to avoid common-mode resonances that typically affect this type of array, loop-shaped transformers are included in the feed network. The common-mode rejection implemented by these transformers allow maintaining the cross-polarization levels to values lower than 10 dB over a 30% relative bandwidth, for an 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. The VSWR maintains levels lower than 3 within a scan volume of 45 from broadside in all planes