A Spherical Conformal Reflectarray Sensor Array for Long-distance Monitoring of Liquid Quality

This paper proposes an innovative reflectarray antenna operating at X-band for environmental monitoring. A sensor array composed of interconnected spherical units is designed. Conformal reflective patches are employed at the top of each sphere for radiation, and the resonant structure is optimized to achieve a periodic size of 20 mm for the reflectarray units. The spheres are horizontally aligned and connected to form a high-performance coherent sensor network. Taking into account the shadowing effect of the feed on the reflected wave in the reflective array antenna, an offset feeding technique is adopted. Each reflectarray unit with a different phase compensation contributes to a high-gain antenna system. This enhancement in information transmission range and accuracy can greatly benefit the environmental monitoring and remote communication abilities of sensors.