Wideband Vivaldi Arrays for Large Aperture Antennas

Singleand dual-polarized arrays of Vivaldi notch elements have been extensively analyzed by using efficient numerical analyses. From these analyses and from experimental studies, element designs and array configurations have been determined to provide more than two octaves of bandwidth while scanning to 45° from broadside in all directions. Parameter studies illustrating the effects of some key design parameters are presented. Vivaldi notch elements are linearly polarized in their principal planes and elliptically polarized in the intercardinal planes. Nonetheless, it has been shown that full polarization information about the radio source can be extracted from the signals received on orthogonal antennas. A few issues related to fabrication and assembly of dual-polarized arrays are discussed.