AI 中文总结
该研究针对可重构智能表面波束转向，提出自动消声室测量方法，结合近场扫描仪与变换技术及低散射支架，通过控制单元编程实现波束转向配置，测量并评估相关参数，验证了方法可行性，给出了不同状态下的增益数据。
AI 中文摘要
可重构智能表面（RIS）需要能够量化编程表面三维散射响应的测量方法，而非仅一个双基地链路的接收功率。本文提出一种用于5GHz左右基于变容二极管的RIS全向表征的自动消声室方法。所开发平台将先进的球形近场扫描仪与适用于天线测量的近场到远场变换相结合，还有用于RIS和激励天线的低散射通用支架。通过集成在室内的控制单元可对多个独立直流电压进行编程以实现远程RIS波束转向配置。利用预测量的相电压特性合成RIS状态，并使用局部角功率平均值与无偏RIS参考进行评估。在5.3GHz的测量作为操作验证：该工作流程可对一维和二维异常反射状态进行编程，在球面上定位所得波束，并从同一数据集中提取目标窗口增益、最大窗口增益和指向误差。对于五个测量的RIS波束转向状态，规定的目标窗口显示相对波束转向增益高达8.8dB，而局部检测到的主瓣窗口显示相对增益高达14.0dB，平均为11.3dB。所报告增益并非RIS的有源放大，而是固定测量配置下的参考归一化局部功率比。
英文摘要
Reconfigurable intelligent surfaces (RISs) need measurement methodologies that quantify the three-dimensional scattering response of a programmed surface, not only the received power of one bistatic link. This paper presents an automated anechoic-chamber methodology for full-sphere characterization of a varactor-based RIS around 5 GHz. The developed platform combines a state-of-the-art spherical near-field scanner with a near-field-to-far-field transformation, which is suitable for antenna measurements, with a common, low-scattering mount for the RIS and the excitation antenna. It enables programming of several independent DC voltages for remote RIS beam steering configuration via a control unit integrated into the chamber, which features a multichannel digital-to-analog converter. The RIS states are synthesized from a pre-measured phase-voltage characteristic and evaluated against an unbiased-RIS reference using local angular power averages. Measurements at 5.3 GHz serve as a proof of operation: the workflow programs one-dimensional and two-dimensional anomalous-reflection states, localizes the resulting beams over the sphere, and extracts target-window gain, maximum-window gain, and pointing error from the same dataset. For five measured RIS beam-steering states, the prescribed target windows show relative beam-steering gains up to 8.8 dB, while the locally detected main-lobe windows show relative gains up to 14.0 dB with an average of 11.3 dB. The reported gain is not active amplification by the RIS; it is a reference-normalized local power ratio for a fixed measurement configuration.
Comments10 pages, 9 figures, Preprint Journal Submission
