A Quadruple-Band Shared-Aperture Antenna Array With Multiband Radiation Pattern Restorations

A quadruple-band shared aperture (QBSA) antenna array is proposed in this article to meet the demands of high-integration multiband base station systems. The QBSA array consists of a low-band (LB) antenna (0.78–1.08 GHz), two groups of middle-band (MB) antennas (1.7–2.1 GHz), and a dual-band high-band (HB) array. This HB array includes dual-band antennas (HB1: 3.4–3.6 GHz and HB2: 4.7–4.9 GHz) along with HB2 antennas, all arranged in an interleaved configuration with each other. The blockage effect caused by the LB antenna results in significant distortion in the radiation patterns of the MB and HB antennas, presenting an unavoidable challenge within the shared-aperture array. To maintain normal radiation patterns, the radiating patches of the LB antenna are converted into electromagnetically transparent structures. This is accomplished by incorporating corresponding multi-FSS structures designed to operate within the frequency bands of the MB and HB antennas. Therefore, the radiated waves from MB and HB antennas can propagate with reduced blockage effect. The MB antenna incorporates dual-band Jerusalem slots within its radiating patches to ameliorate the blockage effect. The assembled QBSA array is measured to validate the simulated results.