Retro-reflective Antenna Design for ISAC

Sammanfattning

The emergence of 6G technology represents a pivotal milestone in telecommunications and device connectivity, transforming a new era for wireless systems, particularly for Internet of Things (IoT) and extended reality (XR) applications. This Master’s thesis investigates the design implementations of Van Atta arrays---passive antenna systems designed to redirect (rather than reflect) incoming signals back toward their source. These arrays serve two main applications. The first prototype features a 4x4 antenna array targeting the 28 GHz frequency band, intended for use in zero-energy (ZE) IoT devices. The second prototype, also a 4x4 antenna array, is designed to operate at 60 GHz and aims to improve gesture recognition and localization in radar systems for XR environments. In order to enable ON-OFF keying (OOK) on the retro-reflected signals, a switching capability using resistive loads on the Van Atta array is evaluated. This thesis presents the design methodology, evaluates simulated performance, and also discusses practical design considerations and fabrication constraints for both frequency bands. By considering metrics such as the monostatic radar cross section (RCS), the designed Van Atta arrays showed the ability to retro-reflect signals for a wide range of angles, as well as the ability to switch the retro-reflection on and off.