发表机构
Univ Rennes, CNRS, IETR - UMR 6164（雷恩大学，法国国家科学研究中心，IETR - UMR 6164）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对无线多端口传感中可访问天线数量受限的瓶颈，提出利用可重构智能表面（RIS）生成测量多样性，通过多路复用去嵌入RIS可编程空中测试夹具重建DUT散射矩阵，实验验证可降低45%重建误差。
AI 中文摘要
无线多端口传感旨在基于远程可访问天线测量的散射参数，远程获取连接到不可直接访问（NDA）天线的多端口待测设备（DUT）的散射矩阵，其中远程可访问天线通过空中（OTA）方式与NDA天线耦合。一个核心瓶颈是所需可访问天线的数量随DUT散射矩阵中未知数的数量而增长。在此，我们通过使用可重构智能表面（RIS）在DUT表征期间生成测量多样性来解决这一瓶颈。我们将该设置解释为通过RIS可编程OTA测试夹具来测量DUT。我们首先使用特定的已知可调负载网络端接NDA天线来表征RIS可编程OTA测试夹具。然后，通过多路复用去嵌入RIS可编程OTA测试夹具，利用在多个RIS配置下获取的DUT测量值来重建DUT的散射矩阵。基于我们根据多端口网络理论制定的系统模型，我们通过优化部署的RIS配置集合来量化并最大化测量序列的多样性。我们在2.45 GHz的富散射无线电环境中实验验证了我们的方法。我们系统地考察了可访问天线数量、RIS配置数量以及RIS配置优化的影响。对于SISO链路（两个可访问天线），优化的RIS配置将100次DUT测量的中位重建均方误差从$1.57{\ imes}10^{-3}$降低45%至$8.59{\ imes}10^{-4}$。这些结果表明，RIS多样性可以补偿有限数量的可访问天线，为工业、生物医学和智能环境RFID系统中的低成本无线多端口传感铺平道路。
英文摘要
Wireless multiport sensing aims to remotely retrieve the scattering matrix of a multiport device under test (DUT) connected to not-directly-accessible (NDA) antennas, based on scattering parameters measured with remotely located accessible antennas that couple over the air (OTA) to the NDA antennas. A central bottleneck is that the required number of accessible antennas grows with the number of unknowns in the DUT's scattering matrix. Here, we address this bottleneck by using a reconfigurable intelligent surface (RIS) to generate measurement diversity during the DUT characterization. We interpret the setup as measuring the DUT via an RIS-programmable OTA fixture. We first characterize the RIS-programmable OTA fixture using a specific known tunable load network to terminate the NDA antennas. Then, we reconstruct the DUT's scattering matrix by multiplexed de-embedding of the RIS-programmable OTA fixture, using measurements of the DUT acquired across multiple RIS configurations. Based on our system model formulated in terms of multiport-network theory, we quantify and maximize the diversity of our measurement sequence by optimizing the deployed ensemble of RIS configurations. We validate our approach experimentally at 2.45 GHz in a rich-scattering radio environment. We systematically examine the influence of the number of accessible antennas, the number of RIS configurations, and the optimization of the RIS configurations. For a SISO link (two accessible antennas), optimized RIS configurations reduce the median reconstruction mean-squared error for 100 DUT measurements by 45% from $1.57{\times}10^{-3}$ to $8.59{\times}10^{-4}$. These results demonstrate that RIS diversity can compensate for a limited number of accessible antennas, paving the way toward low-cost wireless multiport sensing for industrial, biomedical, and smart-environment RFID systems.
Comments13 pages with 6 figures
