An Electromagnetic-Transparent Cascade Comb Dipole Antenna for Multi-Band Shared-Aperture Base Station Antenna Array

• Published in: IEEE transactions on antennas and propagation Vol. 70; no. 4; pp. 2750 - 2759
• Main Authors: Lu, Xiaochi, Chen, Yikai, Guo, Shaojun, Yang, Shiwen
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-04-2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Antenna feeds; Antenna radiation patterns; Antennas; Apertures; Base stations; Couplings; Cross-band decoupling; Dipole antennas; L-band; Mutual coupling; Radiation; shared-aperture antenna; triple-band antenna array
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2021.3137511

In multi-band shared-aperture base station antennas, cross-band mutual couplings always lead to unwanted radiation characteristics. In this article, the influence of the cross-band mutual coupling is investigated from the point of view of induced currents and their secondary radiation fields. A low-band (L-band, 0.76-0.88 GHz) cascade comb dipole antenna is proposed to passively cancel the induced current and therefore suppress the secondary radiation field. Owing to the passive current cancellation capability, the proposed L-band cascade comb antenna does not affect the radiation performance of the middle-band (M-band, 1.9-2.7 GHz) and high-band (H-band, 3.3-3.9 GHz) antennas in stacked multi-band shared-aperture antenna arrays. The proposed L-band antennas are thus electromagnetic-transparent to the M- and H-band antennas. Based on the novel electromagnetic-transparent cascade comb dipole antenna, a triple-band shared-aperture antenna array that consists of the L-, M-, and H-band antennas are developed, manufactured, and measured. Both simulated and measured results validate the attractive features of the cascade comb dipole antenna in multi-band shared-aperture massive MIMO base station antenna array developments.