Reconfigurable Intelligent Surfaces for OTA Testing: Optimization and Initial Results

• Published in: 2023 IEEE Conference on Antenna Measurements and Applications (CAMA) pp. 846 - 851
• Main Authors: Iupikov, Oleg A., Vilenskiy, Artem R., Zhu, Yuqing, Krasov, Pavlo S., Ivashina, Marianna V.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 15-11-2023
• Subjects: Antenna measurements; OTA; Phased arrays; plane wave generator; Position measurement; Reconfigurable intelligent surface; Reflector antennas; Surface waves; Tensors; Wireless communication
• ISSN: 2474-1760; 2643-6795; 2643-6795
• DOI: 10.1109/CAMA57522.2023.10352847

We discuss a new application of RIS for Over-The-Air (OTA) testing of antenna systems and wireless devices, particularly as a cost-effective alternative to millimeter-wave phased-array plane wave generators (PWGs). We present a general approach for the fast modeling and design of the RIS-based PWG. This includes an optimal beamforming algorithm for a RIS and a strategy for configuring the RIS unit cells (UCs) to emulate far-field conditions in the test zone (TZ) with a controllable angle of arrival (AoA) of the incoming plane wave. The proposed approach has been used to derive requirements for a UC of the 21x21 element RIS-based PWG. Our preliminary numerical results demonstrate that the RIS-based PWG allows for synthesizing a TZ with a high-quality plane wave spectrum, where the peak-to-peak variation in field magnitude remains below 0.7 dB, while phase fluctuations do not exceed 5 deg within the range of AoA from -7 deg to 7 deg.