Wideband High-Transparent Dipole Antenna Based on Frequency Selective Surface and Its Applications in Dual-Band Shared-Aperture Array

A lower-band (LB) dual-polarized dipole antenna with wideband high-transparent characteristics based on frequency selective surface (FSS) is proposed. In order to achieve flexible expansion of transparent bands, four U-shaped stubs are symmetrically loaded on the square ring-shaped arm of LB dipole. Thus, the LB arms can be perceived as the band-pass FSS structure at a higher band (HB) with not only one transmission pole but also two transmission zeros, for which the transparent band can be flexibly regulated and finally a wide passband of 1.7 GHz to 2.75 GHz with high transmission coefficient of over −0.5 dB is easily generated by just one-layer structure. Subsequently, the newly designed LB dipole operating at 0.69 GHz to 0.96 GHz (32.7%) is used to construct a dual-band shared-aperture array, where 2 × 2 HB antennas operating at 1.7 GHz to 2.7 GHz (45.5%) are located beneath it. The simulated results agree well with the measured ones, and the performances of LB and HB antennas in the array are consistent with those working alone, indicating the slight mutual interference between the two antennas, which significantly guarantees the dual-band radiation under the same aperture.