A Modular System Design for Chip-Based Reflectarrays at Sub-THz Frequencies

Chip-based reconfigurable reflectarrays (RAs) are a promising option for implementing beam steering in future generations of communication systems at sub-THz frequencies. In this article, an innovative, modular system concept for RAs constructed from chip-integrated subarrays is proposed, which allows flexible scaling to large arrays. The requirements for assembly and interconnection technology are discussed and the beam-steering performance is studied in full-wave simulations. To prove the concept, two RA demonstrators with different, fixed phase progressions are assembled from back-end-of-line subarray chips. Measurements of the far-field radiation pattern at 240GHz confirm the simulated beam-steering capability of the subarray-based RA, and thus validate the proposed concept.