Dual-Band Base Station Antenna Array With Cross-Band Scattering and In-Band Coupling Suppression

Abstract

Dual-band base station antenna array mainly suffers from the drawbacks of cross-band scattering and in-band coupling, which will disturb the radiation performances of the antennas, especially for the high-band (HB) antennas. In this paper, a dual-band base station antenna array with cross-band scattering and in-band coupling suppression is proposed. It contains a low scattering low-band (LB) crisscross-shaped dipole antenna codesigned with four square rings and four patches and a 2×2 HB antenna array. The crisscross-shaped dipole antenna is fed by four L-shaped strips, and a photonic bandgap (PBG) cell is loaded in the middle of each arm of the LB antenna to achieve HB-induced current scattering suppression without affecting the LB antenna, so the radiation patterns distortion from the cross-band scattering can be avoided. As the LB antenna employs crisscross structure, the four rings and patches can be integrated together with the LB antenna on the same substrate, which not only help to broaden the bandwidth, but also act as the array-antenna decoupling surface (ADS). With the codesign of LB antenna and ADS, no extra substrates are required for in-band decoupling. A dual-band base station antenna array prototype is fabricated and measured, showing good performances in LB and HB.