Fully-dynamic and hardware-efficient analog architecture for terahertz wideband hybrid beamforming with multi-channel low-resolution phase shifters

We propose a fully dynamic analog architecture for Terahertz (THz) wideband Hybrid Beamforming (HBF), designed to support ultra-high data rate with low-resolution but multi-channel Phase Shifters (PSs). The proposed architecture employs multiple low-resolution PSs connected in a dynamically parallel configuration to emulate the performance of ideal infinite-resolution PSs. We first derive the minimum number of RF chains and PSs required to achieve performance comparable to fully digital beamforming. We then prove that each high-resolution PS can be effectively replaced by a small set of parallel low-resolution PSs with only marginal performance loss. To further enhance hardware efficiency, we exploit the multi-channel capability of THz PSs by combining multiple PSs with identical phase values. Moreover, an alternating minimization-based algorithm is developed to adaptively optimize the HBF matrices and switch network configurations in response to real-time channel conditions. Simulation results validate the effectiveness of the proposed architecture, demonstrating a substantial reduction in the number of PSs compared to existing schemes, while achieving superior spectral efficiency and energy efficiency. The work offers a hardware-efficient and scalable solution for future THz HBF systems.