A Bowl-Shaped Filtering Antenna With Wideband Cross-Band Scattering Mitigation for Dual-Band Base Stations

The strong cross-band scattering in dual-band base station arrays can cause degraded antenna performance, affecting the radiation performance of the antenna working in higher frequencies. This communication presents a filtered bowl-shaped low-band (LB) antenna covering 0.80–0.96 GHz for dual-band base station arrays, featuring effective wideband cross-band descattering capability in the high band (HB). By incorporating specially designed helical filters into the LB radiators, a significant descattering HB bandwidth reaching 66.7% (1.36–2.72 GHz) of the LB antenna is achieved. To improve the LB impedance matching, the specialized LC circuits are incorporated into the LB balun. These LC circuits, in conjunction with the baffles, also serve to ease the gain fluctuations of the HB antenna placed inside the LB antenna. In addition, the miniaturized aperture size of the LB antenna facilitates enhanced in-band isolation in the array. The LB antenna’s structural stability is guaranteed by the 3-D -printed T-shaped dielectric supports. The measurement results of the fabricated dual-band array agree with the simulations, which validates the efficacy of this design.