Low cross-polarization ultra-wideband arrays (student submission)

This work presents the development of a low cross-polarization ultra-wideband end-fire notch array element, termed the Sliced Notch Antenna (SNA). The proposed element topology solves the long-standing problem of polarization purity degradation in typical end-fire notch arrays (Vivaldi arrays) when scanned in the non-principal planes by re-configuring the high-profile continuous metal Vivaldi fin into disconnected and vertically stacked metal strips. Single-polarized PCB-based SNA arrays and their Vivaldi array counterparts are designed, fabricated, and measured to comparitively evaluate performance. Dual-polarized implementations of both arrays are alike in that they operate over a 10:1 (1.2-12 GHz) bandwidth with VSWR<;2.2 out to θ
₀
= 60° scans as infinite arrays; however simulations suggest the proposed SNA array offers around 20 dB polarization isolation improvement near the highest frequency for D-plane scans out to θ
₀
= {45, 60}°. The technical approach will be expanded further in the presentation and complete measurement results of 19×19 array prototypes will be provided at the conference.