Dual-Band Shared-Aperture Base-Station Antenna Array Using Frequency-Selective Absorbers for Cross-Band Interference Mitigation

The paper proposes a dual-band shared-aperture antenna array using frequency-selective absorbers. In the proposed array, a lower-band (LB) ±45°-polarized dipole antenna is interlaced among four higher-band (HB) ±45°-polarized dipole antennas. To suppress the coupling effect of LB antenna on HB antennas, four Absorbers A are placed above the LB antenna. For the LB antenna, the Absorbers A can absorb the scattering wave from induced HB coupling current, but do not affect the in-band radiation. To mitigate the electromagnetic blockage effect, the LB radiators are designed to pass the HB electromagnetic wave. Each HB antenna element is surrounded by four Absorbers B for suppressing the resonance interference caused by the LB common-mode currents on the HB feeding baluns. Compared with previous works, the proposed array has wider LB of 1.4-2.2 GHz and HB of 3.8-5.2 GHz, higher cross-band isolation of over 33dB and stable radiation patterns. By virtue of the superior advantages, the proposed array is a good solution for multiband communication application scenarios.