RIS-Enhanced Beamwidth-Adjustable Sensing Framework: A Stationary Phase Method-Based Approach

This letter introduces a beamwidth-adjustable sensing beamforming in reconfigurable intelligent surface-assisted communication systems. The proposed approach aims to enhance the detection of potential sensing targets within a broad area centered on the communication user. To achieve this, we develop a channel model that correlates channel gain with spatial offsets and utilize the stationary phase method to derive an optimal numerical solution for adjustable width sensing beamforming. To simplify the process, we propose a low-complexity method that allows for adjustable beamwidth with the ability to achieve zero gain at the beam’s center, making it especially well-suited for integrated sensing and communication applications.