Beam-Steerable Fabry–Pérot Cavity Antenna with Reconfigurable Liquid-Based PRS

The design of a beam steering antenna with a reconfigurable liquid-based metamaterial as a Partially Reflective Surface (PRS) in a Fabry–Pérot cavity (FPC) configuration is presented in this letter. The proposed system is based on a two-layer structure having a source antenna and metamaterial containing, 3D-printed Polylactic Acid (PLA) liquid channels, along with a 9 × 9 square ring elements metamaterial. Beam steering is achieved by varying the reflection amplitude of the reconfigurable metamaterial through the injection of liquid. A prototype of the beam-steering system, operating at 8 GHz, has been fabricated and measured. It achieves beam steering in the range of ±35° for different configurations, with a realized gain of over 10 dBi in each configuration. There is good agreement between simulated and measured results, making the system a good candidate where beam steering with consistent gain is required at low cost and compact size.