Decade-bandwidth low cross-polarization UWB array

The proposed Sliced Notch Antenna (SNA) array fixes the longstanding problem of high cross-polarization radiation in Vivaldi arrays while maintaining their excellent wideband wide-scan impedance performance with a simple reconfiguration of the Vivaldi fins. The enabling technical innovation is the introduction of discontinuities at the upper region of the flared fins that control the ratio of vertical-to-horizontal current density, without introducing sizable reflections. Measurements and simulations suggest a 10:1 (1.2-12 GHz) SNA array operation with good scanning VSWR out to 45°, and about 15 dB polarization purity improvement over a well-designed Vivaldi counterpart.