Broadband Suppression of Common-Mode Current Interference in Dual-Band Base Station Antenna Arrays by Loading an LC Circuit

Authors：Jiang, Jin; Chu, Qing-Xin^*

Source：IEEE Antennas and Wireless Propagation Letters, 2024, 23(1): 224-228.

DOI：10.1109/LAWP.2023.3321941

• Antenna arrays
• Interference
• Loading
• Loaded antennas
• Coaxial cables
• Impedance
• Antennas
• Base station
• common-mode suppressing
• dipole antenna
• dual-polarized
• multiband antenna

This letter proposes a novel, simple method for suppressing common-mode current interference in dual-band dual-polarized base station antenna arrays. By loading a lumped capacitance and inductance (LC) circuit between the outer conductor of the coaxial feeder of the high-band (HB) element and the ground, the common-mode current on the HB element can be entirely suppressed when the low-band (LB) element is excited. The operation mechanism of suppressing common-mode current is analyzed. The proposed method is validated using an array covering 2G/3G/4G communication systems that consist of one LB element operating at 0.69-0.96 GHz and two columns of HB elements operating at 1.7-2.7 GHz. The simulation and measurement results show that this method effectively suppresses the common-mode current on the HB elements while restoring the radiation characteristic of the LB element in broadband.