Frequency-Diverse Integrated Sensing and Backscatter Communication System Utilizing High Scanning-Rate Slot Array Antenna with Inverse Scattering Approach

In this paper, we propose an integrated sensing and backscatter communication system utilizing high scanning-rate slot array antennas (SAAs) in a frequency-diverse configuration, leveraging an inverse scattering approach. This system employs a frequency diversity scheme to facilitate rapid spatial data acquisition, significantly outperforming traditional mechanical and electronic scanning methods in terms of speed and cost-efficiency. The proposed integrated system achieves simultaneous localization, identification, and backscatter communication of tags within cluttered environments. Our approach analyzes backscatter process based on the structural and antenna modes of tags, as well as the presence of clutter scatterers. By modulating the tags between open-circuit and short-circuit states, we effectively extract the structural and antenna mode components. The structural mode component allows us to sense both the tags and the surrounding clutter scatterers, while the antenna mode component is used for precise tag identification by incorporating both inverse scattering and compressive sensing (CS) algorithms. During these processes, channel state information (CSI) is gathered through the antenna mode, enhancing the backscatter communication capability of the system. Additionally, the efficacy of backscatter communication is assessed using the bit error rate (BER) with the maximum ratio combining (MRC) technique. Simulations and experimental results demonstrate that our proposed system can accurately sense and identify tags amidst clutter scatterers while maintaining robust backscatter communication over a 40 MHz bandwidth within the 3.98-4.02 GHz range. These results highlight the significant advantages of employing the proposed frequency-diverse antennas and the inverse scattering approach in integrated backscatter communication and sensing applications.