Varactor-Based Reconfigurable Intelligent Surface for Continuous Phase Control at 28 GHz

IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting (AP-S/URSI), pp. 2412–2415

Abstract

This work presents a varactor diode-based reconfigurable intelligent surface (RIS) design for high-precision beam steering near 28 GHz. Two rectangular patches bridged by a varactor diode form the proposed unit cell and also reduce the biasing complexity. In an infinite periodic environment, without considering varactor loss, the unit cell exhibits a reflection phase coverage of 326° and maintains the reflection loss within -1.03 dB at 28 GHz. Furthermore, the unit cell's performance, including the parasitics of the varactor diode, is verified using a waveguide-based measurement technique, providing an accurate evaluation of its practical performance. A$10 \times 10$unit-cell RIS is constructed using the experimentally validated unit-cell results. Bistatic radar cross section (RCS) results show the precise beam steering capability of the proposed RIS for both normal and oblique incidences of plane waves while maintaining a sidelobe level better than -12.5 dB.

Authors 4

1. Spandan Manna Aachen Institute of High Frequency Technology

   RWTH Aachen University

   Affiliation as printed

   Institute of High Frequency Technology, RWTH Aachen University,Germany

2. Karim El Isa Aachen Institute of High Frequency Technology

   RWTH Aachen University

   Affiliation as printed

   Institute of High Frequency Technology, RWTH Aachen University,Germany

3. Amar Al-Bassam Aachen Institute of High Frequency Technology

   RWTH Aachen University

   Affiliation as printed

   Institute of High Frequency Technology, RWTH Aachen University,Germany

4. Dirk Heberling Aachen Institute of High Frequency Technology

   RWTH Aachen University

   Affiliation as printed

   Institute of High Frequency Technology, RWTH Aachen University,Germany