2D Ray Tracing Analysis of a Dynamic Metasurface Antenna as a Smart Motion Detector

Abstract

We present a ray-tracing analysis of a smart motion detector based on a dynamically reconfigurable metasurface antenna (DMA). A DMA consists of an array of metamaterial radiators excited by a single-port waveguide or cavity. By incorporating simple switchable components into each element and addressing them individually, DMAs can generate a myriad of spatially distinct radiation patterns and alter them as a function of an applied voltage. These patterns have the potential to probe all regions of a room or set of rooms and detect motion, even when operating over an extremely narrow bandwidth. Through the acquisition of time-resolved measurements, the DMA sensor can retrieve temporal signatures and distinguish between different sources of movements. We investigate this sensing paradigm using a ray tracing simulation. We first replicate the trends obtained from recent experiments using our simulation platform to ensure that numerical ray tracing generates data that is a faithful representation of the real-life physics. We then demonstrate that temporal signals obtained in this manner carry information about the nature of the movement. Specifically, by using power spectra and filtering, we are able to extract features that correspond to specific motion patterns. These results constitute the first step toward incorporating DMAs into a smart sensor equipped with learning algorithms that can distinguish between human and non-human motion with high fidelity.

Keywords

• Ray tracing
• antenna radiation patterns
• cavity resonators
• radio frequency (RF)
• sensors
• antenna arrays