Ultrawideband multilayer printed antenna arrays with wide scanning capability

We present different ultrawideband (UWB) multilayer printed arrays with large scanning capability and very low-profile. For each of them, both dielectric arrangement (relative permittivity and thickness of each dielectric layer) and radiating element shape have been simultaneously optimized to reach the best results in terms of bandwidth, scan range, and thickness. Single- and dual-polarized arrays have been obtained with typically a 5.5∶1 bandwidth up to 60° in all planes and a λ high /2 thickness. For the dual-polarization array, cross/co-polarization ratio better than −25 dB may be obtained.