Design of a shared-aperture dual-band dual-polarized microstrip antenna

A multilayer dual-band dual-polarized (DBDP) antenna operating at L and C bands with a shared aperture is presented. The operating frequencies at the band centers are about 1.25 GHz and 5.3 GHz, respectively. The L-band elements are selected as perforated patches to enable the placement of C-band elements within them. Stacked-patch configurations are used to meet the bandwidth requirements, especially in the L-band. Transmission line feed is used by the L-band antenna to simplify the antenna structure. For the C-band elements, slot coupling is used to enlarge the isolation between the bands. The ¿pair-wise anti-phase feeding technique¿ is adopted to minimize the cross polarization level.