Suppression of Cross-Band Coupling Interference in Tri-Band Shared-Aperture Base Station Antenna

• Published in: IEEE transactions on antennas and propagation Vol. 70; no. 6; p. 1
• Main Authors: Chang, Yu-Lin, Chu, Qing-Xin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Antenna radiation patterns; Antennas; Apertures; Array decoupling; base station antenna; Coupling; Dipole antennas; dual-polarized antenna; Interference; MIMO communication; multi-band multi-array; pattern restoration; Radar cross sections; Scattering
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2021.3138531

A tri-band shared aperture (TBSA) antenna is proposed to meet the new requirements of base station antennas for multi-band antennas fusion. The proposed TBSA (P-TBSA) antenna is composed of a lower-band (LB: 790-960 MHz) antenna, two columns of middle-band (MB: 1710-2170 MHz) sub-arrays, and a 4×8 array antenna operating at N78 band (HB: 3.4-3.6 GHz). The LB antenna is located in the center of a shared reflector. The MB sub-arrays are located around the LB antenna with a side-by-side scheme. The HB array antenna is located below the MB and LB antennas for MIMO (multi-input multi-output) application. The cross-band coupling interference existing in the P-TBSA antenna can be divided into scattering interference and common-mode interference, which will seriously deteriorate its performance. To suppress the scattering interference, an LB crossed dipole antenna with low RCS (radar cross section) at both MB and HB and a MB crossed dipole antenna with low RCS at HB are designed. In addition, the method of "path extension" is used to suppressed the common-mode interference. By taking the above measures, the distorted radiation pattern of the P-TBSA antenna are significantly recovered.