DBRAA: Sub-6 GHz and Millimeter Wave Dual-Band Reconfigurable Antenna Array for ISAC

• Published in: IEEE transactions on communications p. 1
• Main Authors: Chen, Kangjian, Qi, Chenhao, Dobre, Octavia A.
• Format: Journal Article
• Language: English
• Published: IEEE 2025
• Subjects: 6G mobile communication; Antenna arrays; Antennas; Array signal processing; Beamforming; Dual band; dual-band reconfigurable antenna array (DBRAA); Hardware; Integrated sensing and communication; integrated sensing and communications (ISAC); millimeter wave (mmWave); Millimeter wave communication; PIN photodiodes; Radio frequency; sub-6 GHz
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2025.3567007

This paper proposes a dual-band reconfigurable antenna array (DBRAA), enabling wireless capabilities in both sub-6 GHz (sub-6G) and millimeter wave (mmWave) bands using a single array. For the sub-6G band, we propose a reconfigurable antenna selection structure, where each sub-6G antenna is formed by multiplexing several mmWave antennas, with its position dynamically adjusted using PIN diodes. For the mmWave band, we develop a reconfigurable hybrid beamforming structure that connects radio frequency chains to the antennas via phase shifters and a reconfigurable switch network. We then investigate integrated sensing and communications (ISAC) in sub-6G and mmWave bands using the proposed DBRAA and formulate a dual-band ISAC beamforming design problem. This problem aims at maximizing the mmWave communication sum-rate subject to the constraints of sub-6G communication quality of service and sensing beamforming gain requirements. The dual-band ISAC beamforming design is decoupled into sub-6G beamforming design and mmWave beamforming design. For the sub-6G beamforming design, we develop a fast search-based joint beamforming and antenna selection algorithm. For the mmWave beamforming design, we develop an alternating direction method of multipliers-based reconfigurable hybrid beamforming algorithm. Simulation results demonstrate the effectiveness of the proposed methods.