Low-Profile Dual-Band Shared-Aperture Base Station Antenna Array Based on High-Impedance Surface Radiator

This letter proposes an ultra-low profile dual-band dual-polarized shared-aperture base station antenna based on high impedance surface (HIS). The low-band (LB) antenna, operating at 0.69-0.96 GHz, is cleverly integrated with the HIS structure. This combination contributes to good impedance matching for the LB antenna in an ultra-low profile setup. Simultaneously, the low-pass HIS serves as a reflector for the high-band (HB) antenna, restoring the radiation pattern of the HB antenna operating at 3.3-3.8 GHz. Due to the in-phase reflection characteristics of the HIS structure, the profile of the HB antenna is significantly reduced. The overall profile of the antenna array is only 0.11 λL. Over the entire operating frequency range, the gain of the LB antenna and HB antenna varies between 10 ± 0.8 dBi and 8.4 ± 0.5 dBi, respectively. The antenna was fabricated and tested, with the test results closely matching the simulation results. This antenna array structure features an ultra-low profile, high gain, and stable radiation patterns, making it suitable for large-scale array base stations.