Terahertz intelligent reflectarray for direction-of-arrival detection and phase modulation

Next-generation wireless communication requires signal sensing and beam-forming communication in an integrated and simultaneous fashion. The terahertz (THz) band offers abundant spectral resources, high spatial resolution, and material fingerprint identification, making it a promising candidate for 6G communication and beyond. However, THz phased array and THz angle-resolved sensor used to be alien to each other, given their distinct functionalities, configurations, and material platforms. Here, we present an ultracompact and integrated angle- and frequency-sensitive THz reflectarray for detecting THz waves’ incident direction and frequency, which concurrently enables electrically controllable phase modulation to facilitate dynamic beam steering for directive communication thereafter. The device employs intra-element coupling to modulate phase and inter-element interaction to detect incident angle or frequency, realizing dual functionality in a unified reflectarray. A prototype reflectarray with 32 elements experimentally achieves a 2-degree angular accuracy and self-adaptive beam tracking in 185 GHz while also demonstrating 1 GHz frequency resolution across the 180–188 GHz range. This scalable architecture opens new avenues, to our knowledge, for intelligent THz wave manipulation in secure communication, sensing, and future electronic systems.