Direct Angle of Arrival (AOA) Estimation Using a Metasurface Antenna With Single Frequency Phaseless Measurements Obeyed Schwarz Inequality

Location estimation has attracted significant interest with the development of wireless communication. The rapid emergence of the fifth generation (5G) and the Internet of Things (IoT) is in great demand for accurate localization, particularly with the increasing interaction between humans and devices. In this article, we propose a method of location estimation using a metasurface antenna. Different from other works that rely on random sampling, we derive an analytical formula for angle of arrival (AOA) estimation with a measurement process that obeys Schwarz inequality. Using only a single metasurface antenna, we can estimate the AOA of one or multiple point sources, the measurement time of which is less than 1 s, with great potential in real-time applications. The proposed method is what-you-see-is-what-you-get, analytical, non-iterative, and narrowband (using only single frequency), providing a cost-effective and complexity-reduced solution for localization applications.