A 1.2–12 GHz Sliced Notch Antenna Array

Historically, Vivaldi arrays are known to suffer from high cross-polarization when scanning in the nonprincipal planes-a fault without a universal solution. In this paper, a solution to this issue is proposed in the form of a new Vivalditype array with low cross-polarization termed the Sliced Notch Antenna (SNA) array. For the first proof-of-concept demonstration, simulations and measurements are comparatively presented for two single-polarized 19 × 19 arrays-the proposed SNA and its Vivaldi counterpart-each operating over a 1.2-12 GHz (10:1) band. Both arrays are built using typical vertically integrated printed-circuit board cards, and are designed to exhibit VSWR <; 2.5 within a 60° scan cone over most of the 10:1 band as infinite arrays. Measurement results compare very favorably with full-wave finite array simulations that include array truncation effects. The SNA array element demonstrates well-behaved polarization performance versus frequency, with more than 20 dB of D-plane θ = 45° polarization purity improvement at the high frequency. Moreover, the SNA element also: 1) offers better suppression of classical Vivaldi E-plane scan blindnesses; 2) requires fewer plated through vias for striplinebased designs; and 3) allows relaxed adjacent element electrical contact requirements for dual-polarized arrangements.