Design and fabrication of low-cost PUMA arrays

Measurements and simulations for various Planar Ultrawideband Modular Antenna (PUMA) arrays are presented. The arrays are based on tightly-coupled printed dipoles above a ground plane and are fully planar, where both the radiating aperture and feed lines are fabricated using low-cost multilayer PCB technology. The dipoles are fed with a novel feeding scheme that suppresses a catastrophic common-mode resonance, thus eliminating the use of feed organizers and external baluns. A product of this novel feeding is the modularity of the aperture (tiled assembly). A proof of concept 16×16×2 dual-polarized array prototype operating over 7-21.5GHz (3:1 bandwidth) was fabricated and measured. The results are in very good agreement with simulations, exhibiting a broadside VSWR = 2.1 and low (-15dB) cross-polarization in the diagonal plane out to 45°. Additionally, an infinite 5:1 PUMA design with broadside VSWR = 2.1, better than 2.9 VSWR at 45° in the H-plane, and cross-pol less than -15dB out to θ = 45° in the D-plane is presented.