Triple-Band Shared Aperture Antennas Based on Dual-Band Pass Frequency Selective Surface Structure

A triple-band shared aperture antennas is proposed, consisting of a low-frequency (LB: 1.7-2.3 GHz) antenna, two middle-frequency (MB: 3.3-3.7 GHz) antennas, and four high-frequency (HB: 6.0-7.3 GHz) antennas, with the MB and HB antennas positioned on either side of the LB antenna. To mitigate the blockage effect of the LB antenna, a low-frequency antenna is designed using a three-layer pass frequency selective surface (FSS) structure as the antenna arm, allowing the MB and HB electromagnetic waves to pass through and radiate without being obstructed by the LB antenna. The FSS unit is inspired by a typical band-pass FSS, with a band-stop patch added above and below it. The coupling between the patches results in a dual-band pass effect, enabling the transmission of MB and HB waves and restoring the deteriorating radiation pattern. Results confirm the stable radiation pattern characteristics of the antennas. This indicates that the proposed method shows promise for the development of 5G MIMO base station antennas.